Astronomy Cast

By Fraser Cain and Dr. Pamela Gay

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Category: Natural Sciences

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 Sep 3, 2018
Listened to the first 70 episodes in a single week. Absolutely hooked. At 110 now but will definitely be exhausting the archives on this one

A Podcast Republic user
 Jul 12, 2018


Astronomy Cast brings you a weekly fact-based journey through the cosmos.

Episode Date
Ep. 509: Fiction to Fact: 3D Printers
The technology of 3D printing is taking off. From tiny home-based 3D printers to larger manufacturing. And of course, 3D printing is going to space with the International Space Station and beyond.
Dec 10, 2018
Ep. 508: 2018 Holiday Gift Guide
We did it, we made it to the end of another year. Once again it’s time to wonder what gifts to get your beloved space nerds. We’ve got some suggestions. Some are brand new this year, others are classics that we just can’t help but continue to suggest.
Dec 03, 2018
Ep. 507: From Fiction to Fact : Ion Drive
Ion engines are a mainstay of science fiction, featured in both Star Trek and Wars. But this is a very real technology, successfully used on several missions out there in the Solar System right now. How do they work and what are the limits?
Nov 27, 2018
Ep. 506: It's not Aliens, Unless it's Aliens
Did you hear that astronomers from Harvard think that the interstellar asteroid Oumuamua was actually an alien solar sail? Is it aliens? Of course it's not aliens. But some day, it'll actually be aliens.
Nov 18, 2018
Ep. 505: Seismology
We’re always interested in the surface features of the planets and moons in the Solar System, but that’s only skin deep. It turns out, these worlds have an interesting inner life too. Thanks to the science of seismology, we can peer into our planet and learn how it works… inside. And we’re about to take that technology to Mars.
Nov 12, 2018
Ep. 504: Radar, Lidar, and Sonar
To really study something, you want to reach out and touch it. But what can you do if you're separated by a huge distance? You reach out with electromagnetic or sound waves and watch how they bounce back. Thanks to radar, sonar and lidar.
Nov 05, 2018
Ep. 503: Gravity Mapping
The Earth looks like a perfect sphere, but down here on the surface we see that there are mountains, rivers, oceans, glaciers, all kinds of features with different densities and shapes. Scientists can map this produce a highly detailed gravity map of our planet. And it turns out, this is very useful for other worlds too.
Oct 29, 2018
Ep. 502: No Touching: Determining Composition of Worlds Remotely
How do you know what something is made of if you can't reach out and touch it? How do we know what planets lights years away have in their atmosphere? What about the rocks all around Curiosity? Or the geysers coming out of Europa and Enceladus? Scientists have a few handy tricks.
Oct 22, 2018
Ep. 501: Water Worlds Revisited
We're not learning that the vast majority of potentially habitable worlds out there are actually icy moons like Europa and Enceladus. Good news, there are hundreds, if not thousands of times more of them than worlds like Earth. Bad news, they're locked in ice. What have we learned about water worlds and their potential for habitability?
Oct 08, 2018
Ep. 500: Live Celebration!
Welcome to episode 500 of Astronomy Cast. To celebrate this momentous occasion, we’re going to look back 500 years into the past to see what we learned about the Universe. And then we’re going to look 500 years into the future.
Sep 17, 2018
Ep. 499: What is the proposed Hubble-Lemaitre Law?
We started out Astronomy Cast with the controversal decision to de-planet Pluto. And here we are, more than a decade later, at the brink of recording our 500th episode when another big decision is coming down from the IAU: whose name goes on the concept that our Universe is expanding: Hubble or Lemaître? It's a big deal and Pamela knows all about it.
Sep 10, 2018
Astronomy Cast: On Hiatus until September 2018
Astronomy Cast will be on hiatus for July and August. Don't worry, we'll be back in September, and will be gearing up for our 500th episode!
Jul 01, 2018
Ep. 498: Dwarf Galaxy Update
The Milky Way has gobbled up dozens of dwarf galaxies and added them to its structure. Today we're going to look at the ongoing hunt for the wreckage of past mergers. And what we've discovered about dwarf galaxies in general.
Jul 01, 2018
Ep. 497: Update on Globular Clusters
Is it globular clusters or is it globeular clusters? It doesn't matter, they're awesome and we're here to update you on them.
Jun 25, 2018
Ep. 496: Update on Stellar Populations I, II, and III
Another update show, this time on the various generations of stars, let's get into it.
Jun 18, 2018
Ep. 495: Update on Asteroids and Prospects of Asteroid Mining
Our knowledge of space is starting to match up with our ability to get out there an explore it. There are several companies working on missions and techniques to harvest minerals from asteroids. What other resources are out there that we can use?
Jun 11, 2018
Ep. 494: Icy Moons Update 2018
Thanks to Cassini and other spacecraft, we've learned a tremendous amount about the icy worlds in the Solar System, from Jupiter's Europa to Saturn's Enceladus, to Pluto's Charon. Geysers, food for bacteria, potential oceans under the ice and more. What new things have we learned about these places?
Jun 04, 2018
Ep. 493: Mars Update 2018
If there's one place we've learned more about in the last 10 years, it's Mars. Thanks to all those rovers, orbiters, landers which are flying overhead, crawling around the surface, and digging into the rich Martian regolith. What have we learned about Elon Musk's future home?
May 28, 2018
Ep. 492: Comets, Asteroids and KBO's
Another topic with plenty of updates. Since we started Astronomy Cast we’ve visited many smaller objects in the Solar System up close, from Ceres and Vesta to Pluto, not to mention a comet. What have we learned?
May 21, 2018
Ep 491: Exoplanet Update 2018
Finally, a big update. Have there been news in the realm of exoplanets? More news that we can possibly cover. But we’ll try our best.
May 14, 2018
Ep 490: What's New with Supernovae
Time for another update, this time we're going to look at what's new with supernovae. And once again, we've got good news, lots of new stuff to report.
May 07, 2018
Ep 489: Black Hole Update
Another update episode, this time we look at what’s new and changed in the research of black holes. And it’s here that we find a lot of substantial new discoveries in the field, so much has been discovered since we first covered black holes a decade ago.
Apr 30, 2018
Ep 488: Dark Energy: 2018 Edition
The updates continue. Last week we talked about dark matter, and this week we continue with its partner dark energy. Of course, they’re not really partners, unless you consider mysteriousness to be an attribute. Dark energy, that force that’s accelerating the expansion of the Universe. What have we learned?
Apr 23, 2018
Ep 487: Dark Matter: 2018 Edition
Last week, we gave you an update in particle physics. This week it’s time to see what’s new in the world of dark matter. Spoiler alert, we still have no idea what it is, but maybe a few more ideas for what it isn’t.
Apr 13, 2018
Ep 486: Particle Physics Update
It’s time for a news update. This time from the field of particle physics. It turns out there have been all kinds of new and interesting particles discovered by the Large Hadron Collider and others. Let’s get an update from Pamela.
Apr 06, 2018
Ep 485: Docking, Refueling, and Transferring
It’s one thing to get to space. But once you’ve made it there, what do you want to do? You’ll probably want to dock with another space ship, deliver cargo, refuel. Today we’ll talk about how all that happens.
Mar 30, 2018
Ep 484: Transfer Orbits and Gravitational Assists
If you want to get around in the Solar System, you’ll want to take advantage of natural gravitational speed boosts and transfer orbits. Whether you’re heading to the outer Solar System or you want to visit the Sun itself, the planets themselves can help you in your journey.
Mar 23, 2018
Ep 483: Stopping in Space
It’s one thing to get from Earth to space, but sometimes you want to do the opposite. You want to get into orbit or touch down gently on the surface of a planet and explore it. How do spacecraft stop? And what does that even mean when everything is orbiting?
Mar 16, 2018
Ep 482: Alternative Ways to Space
Getting to space is all about rockets, but people are trying to figure out other methods that could carry payloads to orbit and beyond. Railguns, airplanes, tethers and more. Today we’ll talk about alternative methods of spaceflight.
Mar 09, 2018
Ep 481: Rockets pt. 3 - Going Faster, Higher, Farther after Fairing Separation
We’ve seen rockets blast off from here on Earth. But that’s only half the story. Rockets have additional stages to push them into trajectories, like transfer orbits and various orbital manouvers. Let’s talk about what happens after the rocket is long gone, beyond our sight.
Mar 02, 2018
Ep 480: Rockets pt. 2- Multi-stage Boosters
The vast majority of rockets are multi-staged affairs. Why is this? What makes this kind of rocket so successful? Today we look at the ins and outs of multi-stage rockets.
Feb 23, 2018
Ep. 479: Rockets pt. 1- What Does "Single Stage To Orbit" Really Mean?
To celebrate the launch of the Falcon Heavy, we figured it was time for an all new series, this time on the rockets that carry us to space. Today we're going to talk about why single stage to orbit rockets are so difficult to carry out.
Feb 16, 2018
Ep. 478: Apollo 8 with Paul Hildebrandt
On Christmas Day, 1968 Frank Borman, James Lovell and William Anders became the first human being to see the far side of the Moon. Their mission, of course, was Apollo 8, the first time human beings had ever left Earth orbit and seen the far side of the Moon. Today we talk all about Apollo 8, with special guest Paul Hildebrandt, director of a new documentary about the mission.
Feb 09, 2018
Ep. 477: State of Exploration: Once and Future Moon
It's been decades since humans set foot on the Moon. Well, it's time to go back, in theory. Of course, we've heard this all before. What are the plans afoot to send humans back to the Moon this time. What hardware will we use, and what other strategies are in the works to make this happen?
Feb 02, 2018
Ep. 476: The Overview Effect
After they’ve been to space, many astronauts report that seeing the world from above has given them a totally new perspective on humanity and the state of our planet. It’s called the Overview Effect. Today we’ll talk about this, and what this perspective can teach us all.
Jan 26, 2018
Updated audio - Ep. 475: Fast Radio Bursts
You know what's fun? Mysteries. Here's one: fast radio bursts. Astronomers have been detecting mysterious one-time signals from across the sky. What's causing them? Nobody knows for sure, but the search is on to get to the bottom of them.
Jan 19, 2018
Ep. 475: Fast Radio Bursts
You know what's fun? Mysteries. Here's one: fast radio bursts. Astronomers have been detecting mysterious one-time signals from across the sky. What's causing them? Nobody knows for sure, but the search is on to get to the bottom of them.
Jan 19, 2018
Ep. 474: Predictions for 2018
Phew, 2018, time to press the reset button and enjoy a whole new year of space exploration and space science. What’s coming up this year? What should we expect to launch, and what will we see in the sky?
Jan 12, 2018
Ep. 473: Remembering the Best Space Science of 2017
2017 was a crazy year for, well, you know. But, it was a great year for space science, a kilonova, extrasolar planets, reusable rockets and more. Let’s look back at the year that was and remember our favorite space science.
Jan 05, 2018
Ep. 472: Best Modern Sci Fi for the Science Lover - Part 4: Bioscience
What happens when the future meets biology? Bioscience science fiction, of course. And that's our focus today as we continue our journey though science-based science fiction.
Dec 29, 2017
Ep. 471: Best Modern Sci Fi for the Science Lover - Part 3: Human Computer Relations
It's time to talk computers, and how we're going to be dealing with them in the future. In our next segment on modern sci-fi, we talk about the future of the human-computer interface.
Dec 22, 2017
Ep. 470: Best Modern Sci Fi for the Science Lover - Part 2: 3D Printing
Our journey through interesting science fiction, this time we talk about speculative fiction dealing with materials science, nanotechnology and 3D printing. It’s a staple in Star Trek, but what other stories deal with it?
Dec 15, 2017
Ep. 469: Best Modern Sci Fi for the Science Lover - Part 1 Space Exploration
We’ve always been fans of science fiction, but we really like our science. Today we’ll talk about some books we’ve been reading recently that do a good job of dealing with the science in science fiction.
Dec 08, 2017
Ep. 468: Simulations for Science and Fun
Astronomers depend on simulations to study the Universe. From relatively straightforward orbital simulations to vast simulations that try to recreate the large scale structure of the Universe from the Big Bang. Today we're going to talk about some of those simulations, as well as tools you can use simulate the Universe.
Dec 01, 2017
Ep. 467: Resonance
Many of the moons and planets across the Universe are in resonance with each other and their star. What causes this resonance, and how can it help us understand the history of planetary formation and migration?
Nov 19, 2017
Ep. 466: Origins of Zero (0)
We depend on zero for our math to work right, but this number was actually invented in fairly recent times. Why do we need zero? Was it inevitable?
Nov 17, 2017
Ep. 465: Exploiting Interfering Light
Electromagnetic radiation, also known as “light” is pretty handy for astronomers. They can use it to directly and indirectly observe stars, nebula, planets and more. But as you probably know, light can act like a wave, creating interference patterns to teach us even more about the Universe.
Nov 10, 2017
Ep. 464: Why the Hype over an Exorock?
Astronomers this week announced that they had discovered an asteroid or comet on a trajectory that brought it from outside the Solar System? Is this the first case of an object from deep space? And what can we learn from this discovery?
Nov 06, 2017
Ep. 463: Pareidolia and the Moon
The man in the moon, the pyramids on Mars. Every cloud, ever. Humans have a tendency to pattern match when they're looking around the Universe - it's called pareidolia. What causes this behaviour, and how can we use this to debunk some hilarious conspiracy theories?
Oct 30, 2017
Ep. 462: Modeling the Weather
Have you noticed that weather forecasting has gotten much better in the last few years? Thanks to weather satellites, weather stations, and better forecasting techniques. How do scientists predict the weather with any kind of accuracy days or even weeks in the future.
Oct 23, 2017
Ep. 461: Measuring the Weather with Satellites
What’s the weather doing? Is it going to rain today? How much? What about temperatures? We depend on modern weather forecasting, thanks, in part to the vast network of weather satellites. What instruments do they have, what orbits do they use.
Oct 16, 2017
Ep. 460: Earth from Afar: Remote Sensing
The space age has given us the ability to look at every corner of the globe in every wavelength. It’s revolutionized our ability to predict the weather, keep track of environmental damage, and watch the world change. Today we look at what missions and technologies give us the ability to watch our world from afar.
Oct 09, 2017
Ep. 459: Arecibo Observatory
And now Cassini’s gone. Smashed up in the atmosphere of Saturn. But planetary scientists are going to be picking through all those pictures and data for decades. Let’s look back at some of the science gathered up by Cassini so far, and we can still learn from this epic journey.
Oct 02, 2017
Ep. 458: The Science of Cassini
And now Cassini’s gone. Smashed up in the atmosphere of Saturn. But planetary scientists are going to be picking through all those pictures and data for decades. Let’s look back at some of the science gathered up by Cassini so far, and we can still learn from this epic journey.
Sep 25, 2017
Ep. 457: Why Did Cassini Have To Die? In Memoriam
It's time to say goodbye to an old friend, NASA's Cassini spacecraft, which has been orbiting within the Saturnian system since 2004. But why does a seemingly healthy spacecraft and mission need to come to an end? Today we look back at the mission, some of the amazing discoveries, and why its finale was necessary.
Sep 18, 2017
Ep. 456: Pluto Revisited
This week, we return to our starting point, where Astronomy Cast began: Pluto. 11 years on, we have a whole new appreciate for the dwarf planet Pluto. We’ve visited it, probed it and taken pictures. It’s time for an update.
Sep 11, 2017
Ep. 455: Your Practical Guide to Colonizing the Milky Way!
This episode was recorded live in St. Louis, MO at the Astronomy Cast Solar Eclipse Escape 2017. Listen as we discuss how humans might be able to colonize the Milky Way!
Aug 28, 2017
Astronomy Cast Extra: Solar Eclipse 101
This episode was recorded live in St. Louis, MO at the Astronomy Cast Solar Eclipse Escape 2017. We're going to give you a set of last minute tips and info to prepare for the Great American Eclipse!
Aug 21, 2017
Ep. 454: Things We're Looking Forward To
As we wrap up season 10 of Astronomy Cast, we look forward to all the instruments, missions and science results on the distant horizon. Think astronomy is exciting already? Just you wait.
Jun 19, 2017
Ep. 453: Favorite Things We've Done These 10 Years
10 years of Astronomy Cast... wow. It's been a long, fun journey. What are some of our favorite episodes and adventures over the decade we've been doing this show.
Jun 11, 2017
Ep. 452: Summer Observing Challenges
Summer is almost here, and for the northern hemisphere, that means warm nights for observing. But what to observe? We're here with a list of events and targets for you to enjoy over the summer. Get your calendars handy, and start organizing some events with your friends, and then get out there!
Jun 05, 2017
Ep. 451: When Can I Buy My Ticket To Space?
Like most of us, you probably want to know what it would be like to travel to space. Maybe not to live, but just to visit. You want to be a space tourist. Good news, there are a bunch of companies working hard to give you the opportunity to fly to space. How long until you can buy a ticket?
May 29, 2017
Ep. 450: Inflatable Habitats
In order to live in space, we'll need to live in a habitat that simulates the temperature, pressure and atmosphere of Earth. And one of the most interesting ideas for how to do this will be with inflatable habitats. In fact, there are a few habitats in the works right now, including one attached to the International Space Station.
May 21, 2017
Ep. 449: Robots in Space!
When you think of a robot, you’re probably imagining some kind of human-shaped machine. And until now, the robotic spacecraft we’ve sent out into space to help us explore the Solar System look nothing like that. But that vision of robots is coming back, thanks to a few new robots in development by NASA and other groups.
May 08, 2017
Ep. 448: Prepping for the Eclipse
On Monday, August 21, 2017, there’s going to be a total eclipse of the Sun, visible to path that goes right through the middle of the United States. You should be making plans to see this, and we’re here to help you know where to go and what to do.
May 01, 2017
Ep. 447: Animals in Space Pt. 3: Dogs, Monkeys and More
For the final episode in our 3-part episode about animals in space, we look at the largest animals to go to orbit. And I’ll just warn you now, this is going to be a really sad episode.
Apr 24, 2017
Ep. 446: Animals in Space Pt. 2: Mice and Other Small Animals
Last week we talked about how the smallest creatures behave in space, but now we move up in size a little to small animals, like mice. What missions have they flown on, and how does microgravity affect their biology?
Apr 17, 2017
Ep. 445: Animals in Space Pt. 1: Insects and Arachnids
We've talked about animals traveling to space in the past, but it's time to take another look, with many other creatures making the trip to the void. Today we're going to talk about the spineless insects and arthropods, and those tough as nails waterbears – tardigrades.
Apr 10, 2017
Ep. 444: Fractals
For this historic 444th episode of Astronomy Cast, we talk about fractals. Those amazing mathematical visualizations of recursive algorithms. What are they, how do you get them? Why are they important?
Apr 03, 2017
Ep. 443: Destroy and Rebuild Pt. 7: Tsunamis
Surf’s up! Today we’re going to be talking about one of the most devastating natural disasters out there: tsunamis. We’re talking huge waves that wreck the seashore. But it turns out, there many ways you can get a tsunami, and one of those has to do with space.
Mar 13, 2017
Ep. 442: Destroy and Rebuild Pt. 6: Magnetic Pole Reversal
If we look back into the geologic record of the Earth, it appears that our planet’s magnetic field flips polarity every few hundred thousand years or so. Why does this happen? When’s it supposed to happen next? Is it dangerous?
Mar 06, 2017
Ep. 441: Destroy and Rebuild, Pt. 5: Continental Drift
Want to travel the world but you don’t have a lot of money? No problem, your continent is drifting across the surface of the Earth right now. In a few million years, you’ll reach your destination.
Feb 27, 2017
Ep. 440: Destroy and Rebuild, Pt. 4: Supervolcanoes!
There are regular volcanoes, and then there are the supervolcanoes. Massive calderas of hot magma of incomprehensible size. Bad news, these things explode randomly and catastrophically. Worse news, there are a bunch around the Earth.
Feb 20, 2017
Ep. 439: Destroy and Rebuild, Pt. 3: How Do We Terraform Earth?
We always want to talk about how we can make Mars more Earth like, but the reality is that we’re making Earth more Venus-Like. We’re Venusforming Earth. What are the various factors we’re impacting on a global scale, and how can we fix them?
Feb 14, 2017
Ep. 438: Destroy and Rebuild, Pt. 2: Geoengineering
We know humans are having an impact on planet Earth, but what if we really put our backs into it, and intentionally tried to change the entire planet? Either to make it better, or to fix some terrible mistake we've made. The technique is called geoengineering. Could it work?
Feb 06, 2017
Ep. 437: Destroy and Rebuild, Pt. 1: The Torino Scale
We love to destroy the universe, and also rebuild it. Today we begin a new series where we destroy and rebuild. Let's talk about some existential threats we face, and ways we could recover, starting with the sword of Damocles hanging over our head: killer asteroids!
Jan 30, 2017
Ep. 436: Common Misconceptions in Probability
Human beings are bad at many things, but we're particularly terrible at understanding probability in a rational way. We underestimate, overestimate and generally mess up probability. We'll try to fix it here, but we'll surely fail.
Jan 23, 2017
Ep. 435: The Butterfly Effect
Small changes can have a big impact. But can a butterfly’s wingbeat in the Amazon really impact the weather halfway across the world? And where do small changes have no impact?
Jan 16, 2017
Ep. 434: Am I On An Alien World?
Once again, science fiction television and movies has let you down. They try to recreate what it might be like on an alien world, but surprise surprise, they mostly get it wrong. That’s because a truly alien world would be different in so many ways, it would blow your mind. Today we’ll help you figure out if you’re on a movie set, or you’ve actually crashlanded on an alien planet.
Jan 09, 2017
Ep. 433: Volcanoes on Mars
Mars is a world of extremes. This unassuming red world is home to the largest and tallest volcanoes in the entire Solar System. In fact, it’s not even a close contest, with Olympus Mons rising 22 km above the surrounding plains, more than twice as tall as Mount Everest. How did Mars get such big volcanoes, and how active is the planet today?
Jan 03, 2017
Ep. 432: Geoglogic Ages of Mars - From Wet and Wild to Desolate Desert
Today, Mars is a desolate wasteland, with dusty red rocks and sand stretching out to the horizon. But billions of years ago, it was a vastly different world. It was blue, with oceans, rivers, lakes, and maybe life? Let’s tell the story of geology on Mars, and we got from that world to the one we see today.
Dec 26, 2016
Ep. 431: The Search for Life on Mars
Enceladus and Europa are all the rage these days, but classic Mars is still a great place to search for life. In fact, ESA’s ExoMars is scanning the planet’s atmosphere for methane, evidence that there might be life there right now. Let’s talk about the search for life on the Red Planet.
Dec 12, 2016
Ep. 430: Coming Home from Mars
Landing on the surface of Mars is very difficult. In fact, it’s probably the toughest planet to land on in the whole Solar System. Today we’ll talk about what it’s going to take to get to and return from Mars!
Dec 08, 2016
Ep. 429: Living on Mars
When Elon Musk announced plans to send humans to Mars, he conveniently left out one important aspect. How are we supposed to survive on a place this hostile to life? Seriously, Mars sucks, and it's going to take some impressive techniques and technologies to make it on the Red Planet.
Nov 28, 2016
Ep. 428: The Moons of Mars
We begin a miniseries on Mars. How many episodes will we do? Who knows? But we start today with a discussion of the two Mars moons, Phobos and Deimos.
Nov 25, 2016
Ep. 427: Click Bait vs Clear Science
Did you hear that Dark Energy doesn't exist any more? Neither does Dark Matter? It turns out that NASA recalculated the Zodiac and now you're an Ophiuchan! Science is hard enough, but communicating that science out to the public when there are publications hungry for traffic is even harder! Here's how to parse the click-bait science titles.
Nov 07, 2016
Ep. 426: Confirmation Bias
I hate to tell you this, but that meat computer in your skull is constantly betraying you. Don’t worry, we’ve all got the same, but fortunately, scientists have learned how this happens, and can help us make sure our science, and lives don’t suffer because of it.
Oct 29, 2016
Ep. 425: Naming Spacecraft
Have you ever noticed spacecraft missions have some pretty cool names? How does anyone decide what to call these things?
Oct 21, 2016
Ep. 424: Lightning
It turns out that nature figured out how to use electricity long before humans did. Lightning storms are common across the Earth, and even the Solar System. What causes this electricity in the sky, and how can science use it?
Oct 17, 2016
Ep. 423: Cyclones
As Hurricane Matthew reminded us, cyclonic storms are a force to be reckoned with. What causes these storms, and how can they form across the Solar System.
Oct 11, 2016
Ep. 422: Geysers
So if you’ve been to Yellowstone National Park, you’ve seen one of the most amazing features of the natural world – geysers. In today’s episode, we’re going to talk about geysers on Earth, and where they might be in the solar system.
Oct 03, 2016
Ep. 421: Space Games!
As you probably know, Fraser is an avid video gamer, especially if it has anything to do with space. Today we turn things around, as Fraser talks about the games he plays, and what he thinks you should be playing too.
Sep 26, 2016
Ep. 420: FIRE!
One of the most dangerous things that can happen inside a spacecraft is fire. Seriously, it’s NASA’s worst nightmare, and for good reason. Fire acts differently in space, and astronauts are always on alert. Here’s why.
Sep 19, 2016
Ep. 419: DragonCon 2016 Live - Rocket Girls
This episode is a special live show that took place at DragonCon 2016 in Atlanta, GA. Pamela hosted a panel of amazing scientists and engineers who all happen to be women, and they discussed the unsung women of NASA and the early Space Age and their roles as “human computers”, and the current climate at JPL for women scientists and engineers.
Sep 15, 2016
Ep. 418: Error 418 – I’m a Teapot!
One of the most familiar asterisms in the night sky is the Teapot, in Sagittarius. Today we’re going to talk about that and have a bonus conversation about Bertrand Russell’s Teapot Argument.
Jun 27, 2016
Ep. 417: Error 417: Expectation Failed
In all fields of science, sometimes more is learned when you fail at what you’re trying to do than when you succeed. So what new science discoveries have failed expectations given us in astronomy?
Jun 20, 2016
Ep. 416: Fireballs from the Sky!
Every now and then we look up and see bright fiery balls falling from the sky. Don’t panic, these are just bolides. Sometimes they leave trails, sometimes they explode, and sometimes they survive all the way to the ground.
Jun 13, 2016
Ep. 415: Temperature of the Universe
The temperature of the Universe can vary a dramatic amount from the hot cores of stars to the vast cold emptiness of deep space. What’s the temperature of the Universe now, and what will it be in the future?
May 30, 2016
Ep. 414: Navigating Far
In our last episode, we talked about what it’ll take to navigate across the Solar System. In this episode we scale things up and speculate how future civilizations will navigate to other stars and even other galaxies.
May 16, 2016
Ep. 413: Navigating Near
It’s hard enough finding your way around planet Earth, but what do you do when you’re trying to find your way around the Solar System? Today we’ll talk about how spacecraft navigate from world to world.
May 09, 2016
Ep. 412: The Color of the Universe
What color is the Universe? Turns out this isn’t a simple question, and one that scientists have really been unable to answer, until now!
Apr 25, 2016
Ep. 411: Science of Sunset Colors
We all enjoy beautiful, multicolored sunsets. But what causes the brilliant oranges, pinks and purples that we see, and why does it change from day to day and season to season?
Apr 18, 2016
Ep. 410: Planet 9 Facts and Fiction
The discovery of Planet 9 has caused a wonderful, confusing uproar and a flood of misinformation in the news and social media. We’ll sort out what we actually know, what things just aren’t true, and what things might be possible!
Apr 11, 2016
Ep. 409: Spin in the Universe
The Solar System is a spinny place. Everything’s turning turning. But if you look closely, there are some pretty strange spins going on. Today we talk about how everything started turning, and the factors that still “impact” them today.
Apr 04, 2016
Ep. 408: Universe Cannibalism
We’ve talked about stellar cannibalism and galactic cannibalism, but now it’s time to take this concept to its logical extreme – universe cannibalism. In the multiverse theory of physics we live in just one of a vast range of universes which might interact with each other. Let’s look for the evidence.
Mar 28, 2016
Ep. 407: Galactic Cannibalism
Remember when we told you that the Universe is a big place, and anything that can go wrong, inevitably does? Today we talk about what happens when galaxies come together. This is particularly pertinent because our Milky Way will collide with Andromeda in the future!
Mar 14, 2016
Ep. 406: Stellar Cannibalism
Most of the time stars hang around for billions of years. But the Universe is a big place, and anything that can go wrong, inevitably does. Today we talk about what happens when these stars come together. The outcome is violent, and fortunately for you, also interesting.
Mar 07, 2016
Ep. 405: Method Not Found
Last week we talked about knowledge, what we do and don’t know. This week we talk about questions which are impossible to ask, where the answers don’t actually exist.
Feb 29, 2016
Ep. 404: The Difference Between: Can’t Know, Don’t Know, and Just Awaiting Better Tech
There the things we know, the things we don’t know, and the things we can’t know. How do we know which one is when when we’re deciding to fund research and direct our scientific inquiry.
Feb 22, 2016
Ep. 403: Funding Big Science: from Alma to LIGO to TMT
How much of a challenge is it to get funding for large projects like LIGO? Fraser and Pamela discuss the difficult issues finding “Big Money.”
Feb 15, 2016
Ep. 402: Gravity Eyes: See The Invisible With The Force
What kinds of things can we see using gravity, that we may not otherwise be able to see? Pamela will fill us in on the Great Attractor, etc!
Feb 08, 2016
Ep. 401: Future Predictions
What do Pamela and Fraser think will happen or be discovered in 2016? What would they like to see in the near future?
Feb 01, 2016
Ep. 400: The State of the Universe
It’s time for us to go back and catch up with all of the projects, news stories, weird star systems, and other topics that need updating!
Jan 25, 2016
Ep. 399: Women in Science
Science is typically a male dominated profession, mostly dudes, not a lot of ladies. From researchers to professors, to law makers, woman have a tough time gaining traction in such a heavily gendered field. Today we’re going to talk about what it takes to make it as a woman in science, what additional hurdles you’ll have to navigate, and what resources are available if you’re being harassed or discriminated against.
Jan 11, 2016
Ep. 398: Seeing Things: Emitting, Reflecting, Ionizing Light
Astronomers gather electromagnetic radiation with the telescopes: mostly visible light. But sometimes they've got to be clever about where they look for these elusive photons. Light can get emitted, absorbed, reflected, and each method tells astronomers a little more about what they're looking at.
Jan 04, 2016
Ep. 397: A Universe From Nothing
One of the biggest, most basic questions you can ask is: “why is there something and not nothing?” The reality is that we don’t know the answer, we might never know the answer. Today we’ll investigate this mystery, recently covered by the physicist Lawrence Krauss in his book of the same name.
Dec 21, 2015
Ep. 396: Family Astronomy for the Holidays
Every year, it’s the same dilemma: what gift should you get for the super space nerd in the family? And if someone has a budding interest in space and astronomy, what can you do to feed their hunger for knowledge? Today we’ll talk telescopes, books and planispheres. Everything you need to avoid a holiday gift disaster.
Dec 14, 2015
Ep. 395: Baryons and Beyond the Standard Model
In the last few episodes, we’ve been talking about the standard model of physics, explaining what everything is made up of. But the reality is that we probably don’t know a fraction of how everything is put together. This week we’re going to talk about baryons, the particles made up of quarks. The most famous ones are the proton and the neutron, but that’s just the tip of the baryonic iceberg. And then we’re going to talk about where the standard model ends, and what’s next in particle physics.
Dec 07, 2015
Ep. 394: The Standard Model - Bosons
All fundamental particles are either fermions or bosons. Last week we talked about quarks, which are fermions. This week we’ll talk about bosons, including the famous Higgs boson, recently confirmed by the Large Hadron Collider.
Dec 05, 2015
Ep. 393: The Standard Model, Leptons and Quarks
Physicists are getting a handle on the structure of the Universe, how everything is made of something else. Molecules are made of atoms, atoms are made of protons, neutrons and electrons, etc. Even smaller than that are the quarks and the leptons, which seem to be the basic building blocks of all matter.
Nov 30, 2015
Ep. 392: The Standard Model - Intro
Humans, cars and planets are made of molecules. And molecules are made of atoms. Atoms are made of protons, neutrons and electrons. What are they made of? This is the standard model of particle physics, which explains how everything is put together and the forces that mediate all those particles.
Nov 23, 2015
Ep. 391: Entrophy
Have you ever been doing thermodynamics in a closed system and noticed that there’s a finite number of ways that things can be arranged, and they tend towards disorder? Of course you have, we all have. That’s entropy. And here in our Universe, entropy is on the rise. Let’s learn about entropy in its specific, thermodynamic ways, and then figure out what this means for the future of the Universe.
Nov 16, 2015
Ep. 390: Occam’s Razor and the Problem with Probabilities
I’m not saying it’s aliens, but it’s aliens. Actually, it’s almost certainly not aliens, or a wormhole, or a multiverse. When scientists discover something unusual, they make guesses about what’s happening. But Occam’s Razor encourages us to consider the probabilities of different events before making any concrete predictions.
Nov 09, 2015
Ep. 389: Roundtable with Paul Sutter
While Pamela and Fraser were at Ohio State University for a symposium in October, they caught up with Paul M. Sutter from Astronomical Observatory of Trieste, who is a visiting scholar at the OSU Center for Cosmology and Astro-Particle Physics. His specialty is cosmic voids. Paul also hosts the podcast “Ask a Spaceman.”
Oct 31, 2015
Ep. 388: Megastructures
This week astronomers announced an unusual transit signal from another star. Although it’s most likely a natural phenomenon, one remote possibility is that this is some kind of alien megastructure. Freeman Dyson and others have considered this idea for decades. Today we’ll talk about the kinds of structures that aliens might want to build.
Oct 26, 2015
Ep. 387: Water on Mars… Again
Have you heard the big news? NASA has reported that Mark Watney is alive and well on the surface of Mars. No, wait, they’ve reported that there’s water on Mars. Didn’t they already report this? Today we’ll update you on the latest discovery and what this means for the search for life on Mars.
Oct 19, 2015
Ep. 386: Orbiting Observers
The atmosphere keeps us alive and breathing, but it really sucks for astronomy. Fortunately, humanity has built and launched space telescopes that get above the pesky atmosphere, where the skies are really clear. Let’s take a look at the past, current and future of orbital observation.
Oct 12, 2015
Ep. 385: Rovers on the Run
Taking pictures of distant worlds is great and all, but the best science happens with boots on the ground. Or in this case... wheels. This week we'll talk all about robotic rovers and the places they rove.
Oct 05, 2015
Ep. 384: Escaping Probes
The gravity of the Earth is a tough thing to escape, but breaking free from the gravity of the Sun is on a whole other level. But humans have achieved this amazing accomplishment, and right now there are several spacecraft leaving the Solar System and never coming back.
Sep 29, 2015
Ep. 383: Approaches to Absolute Zero
The coldest possible theoretical temperature is Absolute Zero, this is the point at which no further energy can be extracted from a system. How are physicists working to get as close as possible to this extreme cold?
Jul 07, 2015
Ep. 382: Degenerate Matter
In some of the most extreme objects in the Universe, white dwarfs and neutron stars, matter gets strange, transforming into a material that physicists call “degenerate matter”. Let’s learn what it is, how it forms.
Jun 30, 2015
Ep. 381: Hollowing Asteroids in Science and Fiction
When we finally make the jump to fully colonizing the Solar System, we're going to want to use asteroids as stepping stones. We can use them as way stations, research facilities, even as spacecraft to further explore the Solar System. Today we'll talk about the science and science fiction of hollowing out asteroids.
Jun 23, 2015
Ep. 380: The Limits of Optics
Astronomers rely on the optics of their instruments, and there are some basic limits that you just can’t avoid. Whatever we look at is distorted by the optics, in fact, a basic property of light means that we’ll never get perfect optics. Here’s why we can’t “magnify and enhance” forever.
Jun 15, 2015
Ep. 379: Fermi's Atom Splitting
When he wasn’t puzzling the mystery of alien civilizations, Enrico Fermi was splitting atoms. He realized that when atoms were split, the neutrons released could go on and split other atoms, creating a chain reaction – and the most powerful weapons ever devised.
Jun 15, 2015
Ep. 378: Rutherford and Atoms
Physicists knew the interior of the atom contained protons, neutrons and electrons, but they didn’t understand exactly how they were organized. It took Ernest Rutherford to uncover our modern understanding.
Jun 08, 2015
Ep. 377: Thomson finds Electron
At the end of the 19th century, physicists were finally beginning to understand the nature of matter itself, including the discovery of electrons – tiny particles of negative charge that surround the nucleus. Here’s how J.J. Thompson separated the electrons from their atoms and uncovered their nature.
Jun 01, 2015
Ep. 376: The Miller-Urey Experiment
Evolution explains how life adapts and evolves over eons. But how did life originate? Chemists Miller and Urey put the raw chemicals of life into a solution, applied an electric charge, and created amino acids – the building blocks of life.
May 18, 2015
Ep. 375: The Search For Life in the Solar System
With the discovery of water ice in so many locations in the Solar System, scientists are hopeful in the search for life on other worlds. Guest Morgan Rehnberg returns to Astronomy Cast to explain the best places we should be looking for life.
May 04, 2015
Ep. 374: Stern-Gerlach Experiment
In the world of quantum mechanics, particles behave in discreet ways. One breakthrough experiment was the Stern-Gerlach Experiment, performed in 1922. They passed silver atoms through a magnetic field and watched how the spin of the atoms caused the particles to deflect in a very specific way.
Apr 27, 2015
Ep. 373: Becquerel Experiment (Radiation)
Antoine Henri Becquerel discovered radioactivity completely by accident when he exposed a chunk of uranium to a photographic plate. This opened up a whole new field of research to uncover the source of the mysterious energy.
Apr 13, 2015
Ep. 372: The Millikan Oil Drop
In 1909 Robert Millikan devised an ingenious experiment to figure out the charge of an electron using a drop of oil. Let's talk about this Nobel Prize winning experiment.
Apr 06, 2015
Ep. 371: Eddington Eclipse Experiment
At the turn of the 20th Century, Einstein’s theory of relativity stunned the physics world, but the experimental evidence needed to be found. And so, in 1919, another respected astronomer, Arthur Eddington, observed the deflection of stars by the gravity of the Sun during a solar eclipse. Here’s the story of that famous experiment.
Mar 30, 2015
Ep. 370: The Kaufmann–Bucherer–Neumann Experiments
One of the most amazing implications of Einstein's relativity is the fact that the inertial mass of an object depends on its velocity. That sounds like a difficult thing to test, but that's exactly what happened through a series of experiments performed by Kaufmann, Bucherer, Neumann and others.
Mar 23, 2015
Ep. 369: The Fizeau Experiment
Light is tricky stuff, and it took scientists hundreds of years to puzzle out what this stuff is. But they poked and prodded at it with many clever experiments to try to measure its speed, motion and interaction with the rest of the Universe. For example, the Fizeau Experiment, which ran light through moving water to see if that caused a difference.
Mar 16, 2015
Ep. 368: Searching for the Aether Wind: the Michelson–Morley Experiment
Waves move through a medium, like water or air. So it seemed logical to search for a medium that light waves move through. The Michelson-Morley Experiment attempted to search for this medium, known as the “luminiferous aether”. The experiment gave a negative result, and helped set the stage for the theory of General Relativity.
Feb 23, 2015
Ep. 367: Spitzer does Exoplanets
We've spent the last few weeks talking about different ways astronomers are searching for exoplanets. But now we reach the most exciting part of this story: actually imaging these planets directly. Today we're going to talk about the work NASA's Spitzer Space Telescope has done viewing the atmospheres of distant planets.
Feb 16, 2015
Ep. 366: HARPS Spectrograph
Almost all the planet hunting has been done from space. But there’s a new instrument installed on the European Southern Observatory’s 3.6 meter telescope called the High Accuracy Radial velocity Planet Searcher which has already turned up 130 planets. Is this the future? Searching for planets from the ground?
Feb 09, 2015
Ep. 365: Gaia
The European Gaia spacecraft launched about a year ago with the ambitious goal of mapping one billion years in the Milky Way. That’s 1% of all the stars in our entire galaxy, which it will monitor about 70 times over its 5-year mission. If all goes well, we’ll learn an enormous amount about the structure, movements and evolution of the stars in our galaxy. It’ll even find half a million quasars.
Feb 02, 2015
Ep. 364: The COROT Mission
Before NASA’s Kepler mission searched for exoplanets using the transit method, there was the European COROT mission, launched in 2006. It was sent to search for planets with short orbital periods and find solar oscillations in stars. It was an incredibly productive mission, and the focus of today’s show.
Jan 26, 2015
Ep. 363: Where Did Earth's Water Come From?
Where on Earth did our water come from. Well, obviously not from Earth, of course, but from space. But did it come from comets, or did the water form naturally right here in the Solar System, and the Earth just scooped it up?
Jan 19, 2015
Ep. 362: Modern Women: Carolyn Porco
It hard to think of a more influential modern planetary scientist than Carolyn Porco, the leader of the imaging team for NASA’s Cassini mission exploring Saturn. But before Cassini, Porco was involved in Voyager missions, and she’ll be leading up the imaging team for New Horizons.
Jan 12, 2015
Ep. 361: Modern Women: Maria Zuber
Maria Zuber is one of the hardest working scientists in planetary science, being a part of six different space missions to explore the Solar System. Currently, she’s the lead investigator for NASA’s GRAIL mission.
Jan 05, 2015
Ep. 360: Modern Women: Jocelyn Bell Burnell
Jocelyn Bell Burnell is an Irish astronomer, best known for being part of the team that discovered pulsars, and the following controversy when she was excluded from the Nobel Prize winning team.
Dec 29, 2014
Ep. 359: Modern Women: Margaret Geller
Margaret Geller is best known for her work on the large scale structure of the Universe, helping us understand the large clusters, super clusters and cosmic filaments that matter clumps into.
Dec 15, 2014
Ep. 358: Modern Women: Sandra Faber
Our focus on female astronomers continues with Sandra Faber, and Professor of Astronomy at UC Santa Cruz. Faber was part of the team that turned up the Great Attractor, a mysterious mass hidden by the disk of the Milky Way.
Dec 08, 2014
Ep. 357: Modern Women: Vera Rubin
It’s time for another series. This time we’ll be talking about famous female astronomers. Starting with: Vera Rubin, who first identified the fact that galaxies rotate too quickly to hold themselves together, anticipating the discovery of dark matter.
Dec 01, 2014
Ep. 356: Rotational Inertia
An object at rest stays at rest, and object in motion tends to stay in motion. This is inertia, defined famously by Isaac Newton in his First Law of Motion.
Nov 24, 2014
Ep. 355: Maker Space: 3D Printing Exploration
Getting stuff into space is complicated and expensive. And what do you do when your fancy space gadget breaks. You print out a new one, of course, with your fancy space 3D printer. It turns out, space exploration is one of the best uses for this technology.
Nov 17, 2014
Ep. 354: Comet Siding Spring vs. Mars
We were witness to a once in a million year event. A close approach of Comet Siding Spring to the Planet Mars. And fortunately, humanity had a fleet of spacecraft orbiting the Red Planet, ready to capture this monumental event in real time. What did we see? What will we learn?
Nov 10, 2014
Ep. 353: Seasons on Saturn
You think we’re the only place that experiences seasons? Well, think again. Anything with a tilt enjoys the changing seasons, and that includes one of the most dramatic places in the Solar System: Saturn, with its rings and collection of moons.
Oct 20, 2014
Ep. 352: Water, Water Everywhere!
Where ever we find water on Earth we find life. And so, it makes sense to search throughout the Solar System to find water. Well, here’s the crazy thing. We’re finding water just about everywhere in the Solar System. This changes our whole concept of the habitable zone.
Oct 06, 2014
Special Episode: Live from DragonCon 2014!
Live from DragonCon 2014! Fraser and Pamela are joined by Les Johnson, Scott Edgington, Erin MacDonald, Roy Kilgard, and Fraser bombards all of these wonderful scientists with the hardest, most complicated questions he can come up with!
Sep 29, 2014
Ep. 351: Asteroid Adventures
Astronomy Cast’s 2014/15 season begins! With Rosetta’s arrival at Comet 67/P, we’re about to see a comet up close and personal. What will it take to explore, exploit and enjoy the asteroids and comets hurtling around our Solar System. And how does science fiction have it all wrong??
Sep 22, 2014
Ep. 350: Space Ship One
SpaceShipOne is the spacecraft created by Scaled Composites to win the $10 million Ansari X-Prize in 2003. It was the first privately built spacecraft to reach 100 km in altitude, twice in two weeks, carrying the equivalent of 3 people. It’s the prototype of the upcoming SpaceShipTwo, created for Virgin Galactic to carry paying passengers into space.
Jul 07, 2014
Ep. 349: Mercury 7 and How the US Picked the First Astronauts
Before the Apollo Program, there was the Gemini Program, and before Gemini came the Mercury Program. 7 elite astronauts chosen from a pool of military test pilots. How did NASA choose these original 7 men?
Jun 30, 2014
Ep. 348: Places with Numbers: 2 Independence Sq (NASA HQ)
Although NASA is spread across the entire US, the headquarters is based right in Washington, DC. And the headquarters building is known as Two Independence Square. This is where past and future space policy for the agency was developed.
Jun 23, 2014
Ep. 347: Live from Balticon!
Enjoy our live show from Balticon!
Jun 09, 2014
Ep. 346: Numbered Places: Area 51
Who knows what mysteries lurk at the military's Area 51 complex in Nevada? Conspiracy theorists and UFO chasers think it's a big alien coverup. But it's probably something more boring, like advanced military aircraft. Let's talk about what we know, and what we think we know about this infamous military base.
May 26, 2014
Ep. 345: Numbered Places: Launch Complex 39
Almost every historic American launch occurred at one place in Cape Canaveral: Launch Complex 39. Good old LC39 was build for the Apollo spacecraft, and then modified for the Space Shuttle program. And now it’s carrying on this tradition for upcoming SpaceX rockets. Let’s explore the history of this instrumental launch facility.
May 19, 2014
Ep. 344: The Rings of Saturn
There’s so much we know about Saturn’s beautiful rings, and yet, there’s so much we don’t know. Morgan Rehnberg, a PhD student at the University of Colorado, Boulder and works with the Cassini mission. Morgan joins Fraser to talk about Saturn’s amazing rings, and how they might have formed.
May 05, 2014
Ep. 343: The Universe is Trying To Kill You
We always say that the Universe is trying to kill you, but we thought we’d really hammer the point home. Dr. Phil Plait from Bad Astronomy joins Fraser Cain for a very special episode of Astronomy Cast. Join us as we hammer out all the ways the Universe wants you dead.
Apr 28, 2014
Ep. 342: Sunsetting Spacecraft
Everything dies, including our technology. But when we've hurtled a few thousands pounds of robotic instrumentation to another planet, it gets a little difficult to shut it down and clean up. What do we do when a mission has reached the end of its useful life?
Apr 15, 2014
Ep. 341: 45th Lunar and Planetary Science Conference
Pamela has a day job, remember? As an astronomer? Recently the 45th Lunar and Planetary Science Conference occurred in the The Woodlands, Texas. Pamela and guest astronomer Sondy Springmann will let us know about the big announcements made at this year's conference.
Apr 11, 2014
Ep. 340: Wernher von Braun
When the United States helped defeat Germany at the end of World War II, they acquired the German rocket scientist Wernher von Braun. He had already developed the German V2 rocket program, and went on to design all the major hardware of the US rocket program. This week, we talk about von Braun’s life and accomplishments.
Apr 07, 2014
Ep. 339: Space Conspiracy Theories
Yes, we actually landed on the Moon. No, aliens didn’t crash land at Roswell. What is it about space exploration that leads to so many conspiracy theories? We’ll try to get to the bottom of these conspiracy theories, poke holes in their ridiculous ideas and help you build your baloney detection kit.
Mar 31, 2014
Ep. 338: Copernicus
It’s safe to say that the Polish astronomer Nicolaus Copernicus shook up the whole Universe. Well, our understanding of our place in the Universe. It was Copernicus who came up with the heliocentric model, placing the Sun at the center of the Solar System, with the Earth as just another planet.
Mar 24, 2014
Ep. 337: Photometry
There's a lot you can learn by just staring at an object, watching how it changes in brightness. This is the technique of photometry, and it has helped astronomers discover variable stars, extrasolar planets, minor planets, supernovae, and much more.
Mar 17, 2014
Ep. 336: Units of Measure
How heavy is a kilogram, how long is a second? How warm is a degree? We measure our Universe is so many different ways, using different units of measurement. But how do scientists come up with measurement tools which are purely objective?
Mar 10, 2014
Ep. 335:Photoelectric Effect
Pop quiz. How did Einstein win his Nobel prize? Was it for relativity? Nope, Einstein won the Nobel Prize in 1921 for the discovery of the photoelectric effect; how electrons are emitted from atoms when they absorb photons of light. But what is it? Let’s find out.
Feb 24, 2014
Ep. 334: Chelyabinsk
Around this time last year a space rock crashed into the Earth above Chelyabinsk, Russia. It brightened the skies for hundreds of kilometers, broke windows and injured many people. Let’s look back at the event. What happened, and what did we learn?
Feb 17, 2014
Ep. 333: When Worlds Collide
Just take a look at the surface of the Moon and you can see it experienced a savage beating in the past. Turns out, the whole Solar System is a cosmic shooting gallery, with stuff crashing into other stuff. It sure sounds violent, but then, we wouldn't be here without it.
Feb 10, 2014
Ep. 332: Stellar Collisions
Out here in the Milky Way’s suburbs, stellar collisions are unheard of. But there are places in the galaxy where stars whiz past each other, and collisions can happen. When stars collide, it’s a catastrophic event, and the stellar wreckage is visible half a galaxy away.
Feb 03, 2014
Ep. 331: Arthur C. Clarke’s Technologies
In our previous episode, we introduced Arthur C. Clarke, the amazing man and science fiction writer. Today we’ll be discussing his legacy and ideas on space exploration. You’ll be amazed to hear how many of the ideas we take for granted were invented or just accurately predicted by Arthur C. Clarke.
Jan 27, 2014
Ep. 330: Arthur C. Clarke
Arthur C. Clarke was one of the greatest science fiction writers of all time. He defined the genre, and revolutionized our ideas about what it will take to become a true space faring civilization. In the first of our two part series on Arthur C. Clarke, we examine the man’s life and his books.
Jan 20, 2014
Ep. 329: Telescope Making, Part 3: Space Telescopes
As we’ve said before, all telescopes really want to be in space. In part 3 of our series on amateur telescope making, we bring you up to speed on the final frontier: amateurs building space telescopes. The hardware and software is available off the shelf, and launches have never been more affordable. The era of amateur space telescopes has arrived.
Jan 13, 2014
Ep. 328: Telescope Making, Part 2: Serious Gear
Some astronomers are control freaks. It’s not enough to buy a telescope, they want to craft every part of the experience with their own hands. If you’re ready, and willing to get your hands dirty (and covered in glass dust), you can join thousands of amateur telescope makers and build your own telescope from scratch.
Jan 06, 2014
Ep. 327: Telescope Making, Part 1: Toys and Kits
Why pick up a low quality, wobbly telescope from the department store when you can craft your own - just like Galileo, and all the great astronomers from history. For a minor investment, you can build a worthy telescope out of spare parts and high quality kits.
Dec 30, 2013
Ep. 326: Atmospheric Dust
When you consider the hazards of spaceflight, it’s hard to get worked up about dust bunnies. And yet, atmospheric dust is going to be one of the biggest problems astronauts will face when they reach the surface of other worlds. Where does this dust come from, and what does it tell us about the history of other worlds, and what can we do to mitigate the health risks?
Dec 23, 2013
Ep. 325: Cold Fusion
The Universe is filled with hot fusion, in the cores of stars. And scientists have even been able to replicate this stellar process in expensive experiments. But wouldn’t it be amazing if you could produce energy from fusion without all that equipment, and high temperatures and pressures? Pons and Fleischmann announced exactly that back in 1989, but things didn’t quite turn out as planned…
Dec 18, 2013
Ep. 324: Sun Grazers
Comets can spend billions of years out in the Oort Cloud, and then a few brief moments of terror orbiting the Sun. These are the sun grazers. Some survive their journey, and flare up to become the brightest comets in history. Others won't survive their first, and only encounter with the Sun.
Dec 09, 2013
Ep. 323: Isotopes
The number of protons defines an element, but the number of neutrons can vary. We call these different flavors of an element isotopes, and use these isotopes to solve some challenging mysteries in physics and astronomy. Some isotopes occur naturally, and others need to be made in nuclear reactors and particle accelerators.
Dec 03, 2013
Ep. 322: SOHO
As we’ve mentioned before, the Sun is a terrifying ball of plasma. It’s a good thing we’re keeping an eye on it. And that eye is the Solar and Heliospheric Observatory, or SOHO. Operating for more than 18 years now, SOHO has been making detailed observations of the Sun’s activity though an almost entire solar cycle. With so many years of operation, SOHO has some amazing stories to tell.
Nov 25, 2013
Ep. 321: Solar Flares
Sometimes the Sun is quiet, and other times the Sun gets downright unruly. During the peak of its 11-year cycle, the surface of the Sun is littered with darker sunspots. And its from these sunspots that the Sun generates massive solar flares, which can spew radiation and material in our direction. What causes these flares, and how worried should we be about them in our modern age of fragile technology?
Nov 18, 2013
Ep. 320: Layers of the Sun
Our Sun isn’t just a terrifying ball of white hot plasma, it’s actually a lot more complex. It’s got layers. And today, we’re going to peel back those layers and learn about the Sun – from the inside out.
Nov 11, 2013
Ep. 319: The Zodiac
Although the Zodiac is best known for astrology nonsense, it has a purpose in astronomy too. The constellations of the Zodiac define the plane of the ecliptic: the region where the Sun, Moon and planets appear to travel through the sky. What are the constellations of the Zodiac, and how do astronomers use them as waypoints?
Nov 04, 2013
Ep. 318: Escape Velocity
Sometimes you’ve just got to get away from it all. From your planet, your Solar System and your galaxy. If you’re looking to escape, you’ll need to know just what velocity it’ll take to break the surly bonds of gravity and punch the sky.
Oct 28, 2013
Ep. 317: Observatories
Have you ever wondered what it’s like to visit one of the big research observatories, like Keck, Gemini, or the European Southern Observatory? What’s it like to use gear that powerful? What’s the facility like? What precautions do you need to take when observing at such a high altitude?
Oct 23, 2013
Ep. 316: Observational vs. Experimental Science
Sometimes you can do science by watching patiently, and sometimes you've just got to get your hands dirty with an experiment or two. These two methods have their advantages and disadvantages for revealing Nature's secrets. Let's talk about how and why scientists choose which path to go down.
Oct 14, 2013
Ep. 315: Particle Accelerators
Who knew that destruction could be so informative? Only by smashing particles together with more and more energy, can we truly tease out the fundamental forces of nature. Join us to discover the different kinds of accelerators (both natural and artificial) and why questions they can help us answer.
Oct 07, 2013
Ep. 314: Acceleration
Put that pedal to the metal and accelerate! It's not just velocity, but a change in velocity. Let's take a look at acceleration, how you measure it, and how Einstein changed our understanding of this exciting activity.
Jul 08, 2013
Ep. 313: Precession
The Earth is wobbling on its axis like a top. You can't feel it, but it's happening. And over long periods of time, these wobbles shift our calendars around, move the stars from where they're supposed to be, and maybe even mess with our climate. Thank you very much Precession.
Jul 01, 2013
Ep. 312: Inverse-Square Law and Other Strangeness
Why don’t we have insects the size of horses? Why do bubbles form spheres? Why does it take so much energy to broadcast to every star? Let’s take a look at some non-linear mathematical relationships and see how they impact your day-to-day life.
Jun 24, 2013
Ep. 311: Sound
Shhhh, shhh. You can stop screaming. That’s because nobody can hear you … in space. But why not? How does sound work here on Earth, and what would it sound like on other planets?
Jun 17, 2013
Ep. 309: Creating a Scienc-y Society
Our modern society depends on science. It impacts the way we eat, work, communicate and play. And yet, most people take our amazing scientific advancement for granted, and some are even hostile to it. What can we do to spread the love of science through education, outreach and media?
Jun 03, 2013
Ep. 308: Climate Change
When it comes to carbon dioxide, just a little goes a long way to warming the planet. Unfortunately, we’ve been dumping vast amounts into the atmosphere, recently passing 400 parts per million. Let’s look at the science of the greenhouse effect, and how it’s impacting our global climate.
May 27, 2013
Ep. 307: The Pacific Ring of Fire
The Pacific Ring of Fire wraps around the Pacific Ocean, including countries like Japan, Canada, New Zealand and Chile. And the inhabitants within those countries are prone to… oh… killer earthquakes, volcanoes and tsunamis. Let’s chat about the history of this region and the kinds of risks they face.
May 20, 2013
Ep. 306: Accretion Discs
When too much material tries to come together, everything starts to spin and flatten out. You get an accretion disc. Astronomers find them around newly forming stars, supermassive black holes and many other places in the Universe. Today we’ll talk about what it takes to get an accretion disc, and how they help us understand the objects inside.
May 13, 2013
Ep. 305: The Spacecraft That Wouldn't Die
Last week we explored the various ways spacecraft can die. But this week, we explore the spacecraft (and the scientists) who never give up, snatching victory from the jaws of defeat. We’ll look at clever solutions to potential spacecraft catastrophes.
May 06, 2013
Ep. 304: Death of a Spacecraft
In the end, everything dies, even plucky space robots. Today we examine the last days of a series of missions. How do spacecraft tend to die, and what did in such heroes as Kepler, Spirit, and Galileo (the missions... not the people).
Apr 29, 2013
Ep. 303: Equilibrium
So many of the forces in space depend on equilibrium, that point where forces perfectly balance out. It defines the shape of stars, the orbits of planets, even the forces at the cores of galaxies. Let's take a look at how parts of the Universe are in perfect balance.
Apr 22, 2013
Ep. 302: Planetary Motion in the Sky
Even the ancient astronomers knew there was something different about the planets. Unlike the rest of the stars, the planets move across the sky, backwards and forwards, round and round. It wasn’t until Copernicus that we finally had a modern notion of what exactly is going on.
Apr 15, 2013
Ep. 301: Planetary Migration
We're so familiar with the current configuration of the planets in the Solar System, but did the planets always orbit in this way? Did they form further out and then migrate inward to their current positions? And what about other star systems out there?
Apr 08, 2013
Ep. 300: What We've Learned in Almost 7 Years
We created Astronomy Cast to be timeless, a listening experience that's as educational in the future as it was when we started recording. But obviously, things have changed in almost 7 years and 300 episodes. Today we'll give you an update on some of the big topics in space and astronomy. What did we know back then, and what additional stuff do we know now?
Apr 01, 2013
Ep. 299: Space Stations, Part 4 — Future Space Station
Sometimes a trilogy needs four parts. We've looked at the history and modern era of space stations but now it's time to peer into the future at some space station concepts still in the works. Most of these will never fly, but the ideas are important. We can't call ourselves a true spacefaring civilization until humans live permanently outside the Earth.
Mar 25, 2013
Ep. 298: Space Stations, Part 3 — International Space Station
And now we reach the third part in our trilogy on space stations, with the largest vehicle ever assembled in space: the International Space Station. Launched in 1998, it now consists of 450 metric tonnes of modules, power systems and spacecraft and is regular host to a handful of astronauts from many countries.
Mar 18, 2013
Ep. 297: Space Stations, Part 2 — Mir
Last week we introduced the history of space stations and focused on the US and Soviet stations that were launched. This week we look at one of the longest running missions ever launched: Mir. From its launch and construction to its fiery finale, Mir helped both the Russians and the Americans extend their understanding of what it actually takes to live in space.
Mar 11, 2013
Ep. 296: Space Stations, Part 1 — Salyut and Skylab
It’s one thing to fly into space, and another thing entirely to live in space. And to understand the stresses and strains this puts on a human body, you’re going to need a space station. In this three-part series, we explore the past, present and future of stations in space, starting with the American Skylab and Russian Salyut stations.
Mar 04, 2013
Ep. 295: The Observable Universe
We understand our place in the Universe because of our direct observations. We can see the light that traveled billions of light years across space to reach us. This sphere of space is the observable universe; everything we can detect. But it’s really just a fraction of the larger, unobservable universe. Today, we’ll talk about both.
Feb 18, 2013
Ep. 294: The Arecibo Observatory
The mighty Arecibo Radio Observatory is one of the most powerful radio telescopes ever built – it’s certainly the larger single aperture radio telescope on Earth, nestled into a natural sinkhole in Puerto Rico. We’re celebrating the 50th anniversary of the construction of the observatory with a special episode of Astronomy Cast.
Feb 11, 2013
Ep. 293: Earthquakes
We always say that the Universe is trying to kill you, but actually, the Earth isn't so fond of you either. Certain parts of planet Earth are prone to earthquakes, where the planet's shifting plates can cause the ground to shake violently. We've had a few devastating earthquakes in recent years, but do they also happen on other worlds?
Feb 11, 2013
Ep. 292: The Oort Cloud
The very outer reaches of the Solar System is a region of space known as the Oort Cloud, which may extend as far as a light-year from the Sun. We only know about the Oort Cloud because that's where long-period comets come from, randomly falling into the inner Solar System from time to time.
Feb 04, 2013
Ep. 291: Shockwaves
As a meteor crashed into the atmosphere above Russia, the world discovered the importance of shock waves; how they're caused and how they propagate through the atmosphere. Today we'll discuss the topic in general and find many examples where shock waves can be created, here on Earth, and out in space.
Jan 28, 2013
Ep. 290: Failed Stars
If you get enough hydrogen together in one place, gravity pulls it together to the point that the temperature and pressures are enough for fusion to occur. This is a star. But what happens when you don't have quite enough hydrogen? Then you get a failed star, like a gas giant planet or a brown dwarf.
Jan 21, 2013
Ep. 289: Cherenkov Radiation
Sure, our atmosphere protects us from a horrible Universe that's trying to kill us, but sometimes it prevents us from learning stuff too. Case in point, the atmosphere blocks highly energetic particles from reaching our detectors. But there's a way astronomers can still detect their influence: Cherenkov Radiation; the cascade of radiation that blasts out as a high-energy particle makes its way through the atmosphere, like a radioactive rainshower.
Jan 14, 2013
Ep. 288: Phases of Matter
As we quickly learn with water, matter can be in distinct phases: solid, liquid, gas and plasma; it all depends on temperature. But why do different materials require different temperatures? And what's actually happening to the atoms themselves as the material switches phases?
Jan 07, 2013
Ep. 287: E=mc^2
It’s mind bending to think about this, but the light in your house, and the house itself are really the same thing. Matter and energy are interchangeable. This was the amazing revelation made by Albert Einstein, with his famous formula: E=mc^2. This is the process that the Sun uses to turn hydrogen into radiation through fusion, and the terrible damage from a nuclear weapon.
Dec 31, 2012
Ep. 286: How to Debunk an End-of-the-World Myth
Everyone is always predicting the end of the world. Someone’s going to tell you that this the year that it’s all going to end… the end of planet Earth… and they’re always wrong. But, someone will eventually be right. Planet Earth is doomed, lets figure out how.
Dec 24, 2012
Ep. 285: How the World Will Really End
Have you checked out the internet lately? Apparently there is some kind of rogue planet causing pole alignment and a killer solar flare that will set off a chain reaction turning the whole universe into strange-matter……. after an alien invasion.
Dec 17, 2012
Ep. 284: Optics
Astronomy depends on bullying light. We reflect it, refract it, bend it, and near it through complex manipulations of light. Though optics we bring we bring the distant universe to our eyepiece.
Dec 10, 2012
Ep. 283: Stellar Motion
Our Universe appears timeless and unchanging, the stars taking their nightly flight across the sky. But over long periods of time, you realize that our local region, and even the entire Milky Way is in constant motion. The constellations we see today would be very different millions or even thousands of years ago. Today we'll discuss stellar motion, how astronomers detect it and how it's useful.
Dec 03, 2012
Ep. 282: Seasons
Spring, Summer, Autumn and Winter. These are the seasons we experience here on Earth as our planet completes an orbit around the Sun. But what’s going on? Why do we experience such different temperatures and weather over the course of 365 days? Do other planets experience the seasons like we do?
Nov 26, 2012
Ep. 281: Explosions in Space
We've all seen the classic science fiction space explosions, full of flames and loud sounds. Beautiful on the screen but, totally lacking in any kind of... science. What's wrong with science fiction? What would chemical and nuclear explosions really look like? What would we hear? And what are some natural explosions that nature detonates in space?
Nov 19, 2012
Ep. 280: The Cosmological Constant
In order to allow for a static Universe, Albert Einstein introduced the concept of the Cosmological Constant Lambda to make the math work out. Once it was discovered that the Universe was actually expanding, he threw the number out calling it his "biggest blunder". But thanks to dark energy, the Cosmological Constant is back.
Nov 12, 2012
Ep. 279: The Hubble Constant
When Edwin Hubble observed that distant galaxies are speeding away from us in all directions, he discovered the reality that we live in an expanding Universe. Hubble worked to calculate exactly how fast this expansion is happening, creating the Hubble constant – which astronomers continue to refine and reference in their research.
Nov 05, 2012
Ep. 278: Animals in Space
We always think about humans in space, but the cold hard reality is that animals have always been first in space. First to fly, first to orbit, and sadly, first to die. Let’s learn about how our animal companions have been our trusty partners in space exploration, and let’s recognize their noble sacrifices over decades of experiments.
Oct 29, 2012
Ep. 277: Orbit
When an object is orbiting the Earth, it’s really falling. The trick, described in the Hitchhiker’s Guide to the Galaxy, is how to throw yourself at the ground and miss. There are several different kinds of orbits, and they are good for different reasons. From suborbital jumps to geostationary orbit, time to learn everything there is to know about going around and around and around.
Oct 22, 2012
Ep. 276: XMM-Newton
The Earth’s atmosphere keeps us alive and blocks x-ray radiation from reaching the surface. In order to understand the universe at the higher energy levels you need to launch a space telescope like the European Space Agency’s XMM-Newton Telescope. Let’s learn about the telescope named for the famous scientist.
Oct 15, 2012
Ep. 275: Isaac Newton
Isaac Newton has been called "the greatest and most influential scientist who ever lived." That sounds about right. He unlocked our modern understanding of gravity and laws of motion, dabbled in optics, philosophy... even alchemy. He was also known to have a bit of a difficult personality. Let's find out everything we can about Isaac Newton.
Oct 08, 2012
Ep. 274: Vesta
There’s some topics on Astronomy Cast that we wait until we are good and ready, until the science is all in. The Dawn mission has completed it’s mapping operations at asteroid Vesta and it’s now moving on to Ceres. This gives us a great opportunity to take a detailed look at this amazing asteroid, report on the science findings, and give you a preview of what’s coming next.
Oct 01, 2012
Ep. 273: Solutions to the Fermi Paradox
In Episode 24 we presented the concept of the Fermi Paradox. In short: Where are all the aliens? Today we’re going to examine the theoretical solutions to this problem. Maybe they’re out there, but just don’t want to talk to us. Maybe it’s too hard to communicate? Maybe there are no other civilizations. Maybe civilizations wipe themselves out when they reach a certain point. So many solutions, none of them satisfactory.
Sep 24, 2012
Ep. 272: Abiogenesis
The Theory of Evolution provides a rich explanation for why we see the diversity of life here on Earth. There are so many lines of evidence, from genetic drift to the fossil record. But how did life start? How did things go from a collection of raw materials to the building blocks of life, giving evolution and natural selection a way to take over? That first step, from non-life to life is called “abiogenesis”, and it’s one of the most important questions science can answer.
Sep 17, 2012
Ep. 271: Who Does What in Space and Astronomy
In past, if you looked up into the sky, you were an astronomer. But everything has gotten so complicated. Now we have astrophysicists, and cosmologists, planetary geologists, and even exobiologists. Who does what, and how do they all interact with one another. If you want to go into space research as a career, which one should you choose?
Sep 10, 2012
Astronomy Cast at Dragon*Con 2012: Space Money
We've probed the deepest recesses of the universe, landed spacecraft and humans on other planets and moons but face it all of this exploration is expensive. Just a single spacecraft can cost billions. Who pays for all this stuff?
Sep 03, 2012
Ep. 270: Inertia
An object at rest tends to stay at rest. An object in motion tends to stay in motion. Isaac Newton dismantled the traditional idea that objects would tend to slow down over time, and described the concept of inertia: the amount an object will resist changes in its motion.
Jun 18, 2012
Ep. 269: Mass
Last week we talked about energy, and this week we’ll talk about mass. And here’s the crazy thing. Mass, matter, the stuff that the Universe is made of, is the same thing as energy. They’re connected through Einstein’s famous formula – E=mc2. But what is mass, how do we measure it, and how does it become energy, and vice versa.
Jun 11, 2012
Ep. 268: Energy
Our entire civilization depends on energy: getting it, converting it, burning it, and conserving it. But how do physicists think about energy? How do they measure and quantify it. And what is energy's special relationship with mass?
Jun 04, 2012
Ep. 267: Infinities
Forever is a funny thing. Today we’re going to talk about infinities. That’s right, all the different kinds of possible infinities. How you add them, subtract them, and use them to think about the scale of the Universe
May 28, 2012
Ep. 266: Archimedes
It's time to look deep into history to the birthplace of modern mathematics - Ancient Greece. And the most famous mathematician of the time was Archimedes. We use many of his mathematical theories and inventions to this day; others are steeped in legend and mystery.
May 21, 2012
Ep. 265: Arthur Eddington
We can thank Arthur Eddington for much of our current understanding of stars. He provided some of the breakthrough concepts that explain what’s going on, deep inside the hottest places in the Universe. Sadly, the spacecraft associated with his name wasn’t so successful.
May 14, 2012
Ep. 264: Hazards of Spaceflight
We hold all these romantic notions about humans exploring the Solar System, turning humanity into a true spacefaring race. But the cold hard reality is that space, really the entire Universe, is trying to kill you. Any humans venturing out into space will face all kinds of hazards.
May 07, 2012
Ep. 263: Radioactive Decay
Nothing lasts forever, even atoms. Heavier elements decay into lighter elements, releasing energy as radiation. But thanks to this radiation, astronomers can get a glimpse into what's going on inside distant start. Let's take a look at the whole process of radioactive decay, the different events that happen, and how humans use this fundamental force of nature for our own needs.
Apr 30, 2012
Ep. 262: Solar Sails
Wouldn’t it be cool to explore the cosmos, powered only by sunlight caught by your shimmering solar sail? It sounds like science fiction, but it’s serious science – a test sail has even been sent to orbit. It might even be a way to travel from star to star.
Apr 23, 2012
Ep. 261: Lasers and Masers in Astronomy
Last week we introduced the science of lasers and masers. This week we apply that knowledge to our favourite field: astronomy. Learn how naturally forming masers teach us about the cosmos, and how the artificially produced lasers help us gather better science.
Apr 16, 2012
Ep. 260: The Technology of Lasers and Masers
Just when you think you understand it, light will do some amazing things. Just look at the discovery of lasers, and their use in almost every technology you can think of: from cutting, to transmitting information to, yes, astronomy. And nature has figured out its own version of laser technology, called the maser, which has kept astronomers puzzled and excited for years.
Apr 09, 2012
Ep. 259: Exploration of Venus
Mars gets all the attention, but you might be surprised to know how much Venus has been explored. From initial telescope observations and the early flyby missions, to the landers… yes landers and orbiters. We know quite a lot about Venus, but the planet sure didn’t give up its secrets easily.
Apr 02, 2012
Ep. 258: Viking Landers
Last week we talked about the orbiter portion of the Viking Missions. But that was only half the adventure. Each Viking spacecraft carried a lander as well, which touched down on the surface of Mars, searching for evidence of past and current life. And what they discovered is still up for debate.
Mar 26, 2012
Ep. 257: Viking Orbiters
Spirit, Opportunity and Curiosity get all the news now, but it was NASA's Viking Missions that gave us our first close up view of the surface of Mars. These twin missions, both made of orbiter and lander set the stage for the exploration of Mars, demonstrating that we could actually reach the surface of Mars, and study the soil up close. Today, let's talk about the Viking Orbiters.
Mar 19, 2012
Ep. 256: Resolution
When it comes to telescopes, astronomers really just care about resolution: how much can you see? Your resolution defines how much science you can get done, and it depends on your gear, wavelength, and conditions. Putting a telescope in space really helps too.
Mar 12, 2012
Ep. 255: Observing Hydrogen
Hydrogen is the most common element in the Universe, formed at the beginning of everything in the Big Bang. It's the raw material of stars, gathering together through mutual gravity into vast nebulae. Astronomers can learn so much looking for hydrogen in the Universe. Here's why, and how they do it.
Mar 05, 2012
Ep 254: Reflection and Refraction
Light can do some pretty strange stuff, like pass through objects and bounce off them; it can be broken up and recombined. In fact, everything we "see" is actually the end result of reflection and refraction of light. Time to understand how it all works.
Feb 27, 2012
Ep. 253: Rayleigh Scattering
Next time a kid asks you, why is the sky blue? Answer them: because of Rayleigh scattering. If they’re not happy with that answer, feel free to expand based on the knowledge we’re about to drop today, right into your brain.
Feb 20, 2012
Ep. 252: Heisenberg Uncertainty Principle
Quantum theory is plenty strange, but one of the strangest discoveries is the realization that there’s a limit to how much you can measure at any one time. This was famously described by Werner Heisenberg, with his uncertainty principle: how you can never know both the position and motion of a particle at the same time.
Feb 13, 2012
Ep. 251: Messier Catalog
Have you ever looked into the sky and noticed a fuzzy blob? That’s a Messier Object, carefully cataloged by Charles Messier to make it easier to find comets. We’ll learn about the history of the catalog, Messier’s criteria and some of the prominent objects you’ll see in the sky.
Feb 06, 2012
Ep. 250: Precision
Accuracy, precision and reproducibility. These are the foundations of science that make our progress possible. How do these play into a scientist’s daily activities? And just how precise can we get with our measurements?
Jan 30, 2012
Ep. 249: Schrödinger’s Cat
You’ve probably all heard of Schrödinger’s Cat, that strange thought experiment designed by Erwin Schrödinger to show how the strange predictions of quantum theory could impact the real world. No cats will be harmed in the making of this episode, maybe.
Jan 23, 2012
Ep. 248: Carina Constellation
Time for another detailed look at a constellation; one of the most fascinating in the sky, but hidden to most of the northern hemisphere: Carina. Home to one of the most likely supernova candidates we know of: Eta Carinae. Let’s talk just about this constellation, how to find it, and what you can discover in and around it.
Jan 16, 2012
Ep. 247: The Ages of Things
This is going to be one of the “how we know what we know” kind of shows. How do scientist determine the age of things? How do we know the age of everything from stone tools, to the age of the Earth, to the age of the very Universe.
Jan 09, 2012
Ep. 246: What If Something Was Different?
The number of moons, the age of the Sun, and our placement in the Milky Way all had an impact on the formation of the Earth and the evolution of life on our planet. But what if things were different? What would be the implications?
Jan 02, 2012
Ep. 245: Calendars
Our lives are ruled by calendars. And calendars are ruled by astronomy. As we near the end of 2011, and get ready to ring in the new year, let’s discover the astronomy underlying the days, weeks, months and years that segment our lives.
Dec 26, 2011
Ep. 244: Io
If you want to see one of the strangest places in the Solar System, look no further than Io, Jupiter's inner Galilean moon. The immense tidal forces from Jupiter keep the moon hotter than hot, with huge volcanoes blasting lava hundreds of kilometres into space.
Dec 19, 2011
Ep. 243: Tunguska Event
On June 30th, 1908 “something” exploded over the Tunguska region of Siberia, flattening thousands of square kilometres of forest, and unleashing a force that rivalled the most powerful nuclear weapon ever detonated. What was it? What could unleash that kind of destructive energy? And will it happen again?
Dec 12, 2011
Ep. 242: Torino Scale
When you hear of a looming asteroid strike, do you wonder what to do? Should you go into your underground bunker, evacuate the state, or leave the planet? Fortunately, astronomers have developed the Torino Scale – a handy measurement that incorporates both the risk of a strike with the amount of devastation.
Dec 05, 2011
Ep. 241: Astrophotography, Part 3: Image Processing
Time for part 3 of our tour through the hobby of astrophotography. You’ve set up your gear, taken some clear images. Now we’re going to help you turn that raw data into the kind of amazing photographs you see in books and on the web.
Nov 28, 2011
Ep. 240: Astrophotography, Part 2: Techniques
In the first episode, we talked about the gear you'll need for your expensive astrophotography hobby. This week we continue our discussion, and talk about the techniques you'll use to get those amazing photographs. Bring a hot drink, and get ready for some cold nights. But trust us, it'll all be worth it.
Nov 21, 2011
Ep. 239: Astrophotography, Part 1: The Gear
No matter how good your telescope is, you're never going to see the same detail and colours as the photographs. To take amateur astronomy to the next level, you really need to attach a camera to your telescope. Welcome to the hobby of astrophotography. Fair warning, this hobby could bankrupt you.
Nov 14, 2011
Ep. 238: Solar Activity
The Sun looks like a harmless burning ball of fire in the sky: warm, life-giving and forever unchanging. But we know better, don’t we. It’s really a massive ball of churning hydrogen plasma, encased in twisting magnetic field lines, speckled with sunspots, and constantly disgorging vast plumes of radiation and charged particles. The Sun is very active indeed.
Nov 07, 2011
Ep. 237: Spooky Space Sounds
To help you out with your halloween parties, we’ve collected together the spooky sounds of space. Every piece of audio we’re about to play might sound like it comes from a terrifying nightmare dimension, but it’s really just a natural space phenomena.
Oct 31, 2011
Ep. 236: Einstein Was Right
At least once a week we get an email claiming that Einstein was wrong. Well you know what, Einstein was right. In fact, as part of his theories of Special and General Relativity, Einstein made a series of predictions about what experiments should discover. Some explained existing puzzles in science, while others made predictions that were only recently proven true.
Oct 24, 2011
Ep. 235: Einstein
What can we say about Einstein? Albert Einstein! Lots, actually. In this show we’re going to talk about the most revolutionary physicist… ever. He completely changed our understanding of time, and space, and energy, and gravity. He made predictions about the nature of the Universe that we’re still testing out.
Oct 17, 2011
Astronomy Cast at Dragon*Con 2011: Strange Stuff in Space
This is an impromptu episode of Astronomy Cast that we recorded during Dragon*Con 2011. Pamela was scheduled to speak with a panel about strange things in space, but she ended up being the only person there. So Fraser jumped in, and this was what we did. We mostly talked about unusual things in the Solar System, but a few things in the rest of the Universe.
Oct 15, 2011
Ep. 234: Lunar Phases
The Moon is a stark reminder that we actually live in a Universe filled with stars and planets and moons. The changing phases of the Moon show us the relative positions of the Earth, the Sun and the Moon as they interact with one another. Let's learn about the different phases, the geometry of the whole system, and some of the interesting science wrapped up with our fascination of our only natural satellite.
Oct 10, 2011
Ep. 233: Radar
Radar is one of the those technologies that changed everything: it allows boats and aircraft to “see” at night and through thick fog. But it also changed astronomy and ground imaging, tracking asteroids with great accuracy, allowing spacecraft to peer through Venus’ thick clouds and revealing secrets beneath the Earth’s shifting sands.
Oct 03, 2011
Ep. 232: Galileo Spacecraft
In last season’s thrilling cliff hanger, we talked about astronomer superhero Galileo Galilei. Will a mission be named after him? The answer is yes! NASA’s Galileo spacecraft visited Jupiter in 1995, and spent almost 8 years orbiting, changing our understanding of the giant planet and its moons.
Sep 26, 2011
Ep. 231: Galileo Galilei
It’s hard to imagine a more famous astronomer than Galileo Galilei. He’s widely recognized as the very first person to point a telescope at the skies and then study what he saw. Galileo discovered the moons of Jupiter, the phases of Venus, and much more. But it was his controversial stance on the nature of the Solar System that brought him into conflict with the church.
May 02, 2011
Ep. 230: Christiaan Huygens
And now we finish our trilogy of Saturnian astronomers and missions with a look at the Dutch astronomer and mathematician, Christiaan Huygens. It was Huygens who discovered Titan, and figured out what Saturn’s rings really are, so it makes sense that a probe landing on the surface of Titan was named after him.
Apr 25, 2011
Ep. 229: Cassini Mission
Last week we talked about the Italian astronomer Giovanni Cassini. This week we’ll talk about the mission that shares his name: NASA’s Cassini Spacecraft. This amazing mission is orbiting Saturn right now, sending back thousands of high resolution images of the ringed planet and its moons.
Apr 18, 2011
Ep. 228: Giovanni Cassini
Another two parter, coming at you. This week we talk about the Italian astronomer, Giovanni Domenico Cassini, best known for discovering Saturn's moons and the biggest division in Saturn's rings. Cassini made many other important discoveries in the Solar System, and in the fields of physics and astronomy.
Apr 11, 2011
Ep. 227: The Big Dipper
We wanted to spend a few shows talking about some of the most recognizable constellations in the night sky. We've chatted about Orion the Hunter, but now we're going to talk about the Big Dipper, also known as Ursa Major, or the Great Bear - apologies to our southern hemisphere listeners.
Apr 04, 2011
Ep. 226: Weather
How's the weather? Maybe a better question is... why's the weather? What is it about planets and their atmospheres that create weather systems. What have planetary scientists learned about our Earth's weather, and how does this relate to other planets in the Solar System. What is the most extreme weather we know of?
Mar 28, 2011
Ep. 225: Ice in Space
A huge part of the Solar System is just made of ice. There are comets, rings, moons and even dwarf planets. Where did all this ice come from, and what impact (pardon the pun) has it had for life on Earth?
Mar 21, 2011
Ep. 224: Orion
Most people know how to find two constellations: the Big Dipper, and Orion the Hunter. You can teach a small child to find Orion, and at the right time of year, they'll find it in seconds. There's so much going on in this spectacular constellation, from the star formation in the Orion Nebula to mighty red supergiant Betelgeuse, ready to explode. Let's learn about the history and science of the constellation Orion.
Mar 14, 2011
Ep. 223: The Transit of Venus
Since the planet Venus is closer in to the Sun than Earth, there are rare opportunities to see it pass directly in front of our parent star. This is known as a planetary transit, and thanks to the geometry of the Earth and Venus, they only happen a couple of times a century. The transits of Venus have been used by astronomers to unlock the scale of the Solar System, and there’s another one just around the corner.
Mar 07, 2011
Ep. 222: The Decadal Survey
In episode 198 we explained how space missions are chosen, and introduced the Decadal Survey. Since the time we recorded that episode, the full Decadal Survey for planetary science has been released, explaining the science goals for planetary geologists over the next 10 years. We thought we’d take an episode and give you an overview of all the science coming your way.
Feb 28, 2011
Ep. 221: Geomorphology
When we look around our planet, we see a huge variety in landforms: mountains, valleys, plateaus, and more. Continents rise and fall over the eons, providing geologists with a history of the planet's evolution. The study of these changes is known as geomorphology, and the lessons we learn here on Earth apply to the other objects in the Solar System.
Feb 21, 2011
Ep. 220: Mass Extinction Events
The Earth seems like a safe place, most of the time. But we have evidence of terrible catastrophes in the ancient past. Times when almost all life on Earth was wiped out in a geologic instant. What could have caused so much devastation? And will something like this happen again?
Feb 14, 2011
Ep. 219: Planck Mission
Another mission named after a famous physicist. This time we're looking at the Planck mission, designed to study the Cosmic Microwave Backgorund Radiation over the entire sky. Like the previous WMAP mission, this will help astronomers understand the first moments after the Big Bang.
Feb 07, 2011
Ep. 218: Max Planck
It's time for another action-packed double episode, where we meet a man and his mission. This time around its German physicist Max Planck, considered to be the father of quantum theory - he was later granted a Nobel Prize for just that discovery. Let's take a trip back just over 100 years to learn about the man who changed our understanding of the very small.
Jan 31, 2011
Ep. 217: Stellar Classification
Have you ever heard an astronomer utter these words? Oh be a fine girl and kiss me. They’re not being romantic, they’re trying to remember the different ways to organize stars, as detailed nicely on a Hertzsprung–Russell diagram. Let’s learn what all those letters mean, and what differentiates a type O star from a type G.
Jan 24, 2011
Ep. 216: Archaeoastronomy
The Sun, Moon, stars and planets are visible to the unaided eye, and so they have been visible to astronomers since before recorded history. Some of the earliest records we do have tell us what the ancient astronomers thought about the heavens, and how they used the changing night sky in their daily lives.
Jan 17, 2011
Episode 215: Light Echoes
Just as sound can echo off distant objects, light can echo too. And the echoes of light bouncing off stellar remnants, black hole accretion disks, and clouds of gas and dust provide astronomers with another method of probing the distant cosmos.
Jan 10, 2011
Episode 214: Space Tourism
Have you ever wanted to go to space, but lacked the... everything... to be an astronaut? A whole new industry of space tourism will take you where you need to go. There are new companies offering zero-G flights, sub-orbital flights, and there have even been paying customers who have gone into orbit. Is this going to be space travel for the rest of us?
Jan 03, 2011
Episode 213: Supermassive Black Holes
It's now believed that there's a supermassive black hole lurking at the heart of every galaxy in the Universe. These monstrous black holes can contain hundreds of millions of times the mass of our own Sun, with event horizons better than the Solar System. They're the source of the most energetic particles in the Universe, the brightest objects in the Universe, and the place where the laws of physics go to get mangled.
Dec 27, 2010
Episode 212: GPS Navigation
Last week we talked about the old way navigators used to find their way around the planet; by looking at objects in the sky, and doing some tricky math. The new navigation system, of course, is the Global Positioning System, and it helps you find your spot on the planet with amazing accuracy. Let's see where the system came from, and how it works.
Dec 20, 2010
Episode 211: Celestial Navigation
Before there was GPS, navigators had to rely on the Sun and the stars to find their way around the Earth. It's easier than it sounds, if you've got the right instruments, clear skies, and a really accurate clock. Let's examine the history of celestial navigation, learn about the different methods, and then give you some practical ways that you can go out and learn how to do this for yourself.
Dec 13, 2010
Episode 210: Mars Exploration Rovers
The twin Mars Exploration Rovers, Spirit and Opportunity, have been crawling around the surface of Mars since early 2004 – years longer than they were expected to live. And what they have discovered there on Mars has given scientists their best understanding of Martian geology over the last few billion years. Let’s investigate these amazing rovers and their ongoing mission.
Dec 06, 2010
Episode 209: Exotic Life
We don’t like cover news on Astronomy Cast, but sometimes there’s a news story that’s interesting, complicated, and rapidly unfolding – and it happens to cover an area that we haven’t talked much about. So today we thought we’d talk about the discovery of arsenic-based life, and exotic forms of life in general. Maybe we need to redefine our definition of life. Or maybe we just got introduced to some distant cousins.
Nov 29, 2010
Episode 208: Spitzer Space Telescope
Last week we talked about Lyman Spitzer, and this week we’ll take a look at the orbiting observatory that bears his name: the Spitzer Space Telescope. Designed to see into the infrared spectrum, Spitzer has returned images of objects that were previously hidden to astronomers by thick shrouds of gas and dust.
Nov 22, 2010
Episode 207: Lyman Spitzer
Time for another action-packed double episode of Astronomy Cast. This week we focus on the Lyman Spitzer, a theoretical physicist and astronomer who worked on star formation and plasma physics. Of course, this will lead us into next week’s episode where we talk about the mission that bears his name: the Spitzer Space Telescope.
Nov 15, 2010
Episode 206: Fission
Last week we talked about fusion, where atoms come together to form heavier elements. This week, everything comes apart as we talk about nuclear fission. How it occurs naturally in the Universe, and how it has been harnessed by science to produce power, and devastating weapons.
Nov 08, 2010
Episode 205: Fusion
When the Universe formed after the Big Bang, all we had was hydrogen. But through the process of fusion, these hydrogen atoms were crushed into heavier and heavier elements. Fusion gives us warmth and light from the Sun, destruction with fusion bombs, and might be a source of inexpensive energy. We'll also look into the controversy of cold fusion.
Nov 01, 2010
Episode 204: Temperature
Now we're going to answer a question that a 4-year old might ask - what is temperature? Why are things hot and why are they cold? How hot or cold can they get? And how is this all important for astronomy?
Oct 25, 2010
Episode 203: Europa
Europa is the smallest of the Jovian satellites, but it might be one of the most exciting spots in the Solar System. When NASA’s Voyager spacecraft flew past the moon, they discovered huge cracks in its icy surface. Is it possible that Europa has a huge ocean of liquid water, and maybe even life? This is a world that needs more investigation.
Oct 18, 2010
Episode 202: The Planets at Gliese 581
With the discovery of a planet in the habitability zone of Gliese 581, the chances of finding life on other worlds is just getting better and better. Let’s take a look at the discoveries made at Gliese 581, provide some perspective on the real chances of life, and talk about what might come next.
Oct 11, 2010
Episode 201: Titan
Titan is Saturn’s largest moon, and the second largest moon in the Solar System. It’s unique in the Solar System as the only moon with an atmosphere. In fact, scientists think that Titan’s thick atmosphere – rich in hydrocarbons – is similar to the early Earth, and could give us clues about how life got started on our planet.
Oct 04, 2010
Episode 200: The Mariner Program
The first interplanetary series of missions was the American Mariner program. These successful spacecraft visited Mercury, Venus, and Mars, and laid the groundwork for the US missions to the outer planets. Let's take a look at the program and their incredible accomplishments.
Sep 27, 2010
Episode 199: The Voyager Program
Launched in 1977, the twin Voyager spacecraft were sent to explore the outer planets: Jupiter, Saturn, Uranus and Neptune. Because of a unique alignment of the planets, Voyager 2 was the first spacecraft to ever make a close approach to Uranus and Neptune. Let’s take a look back at this amazing program, and see where the spacecraft are today.
Sep 20, 2010
Episode 198: How is a Space Mission Chosen?
Space missions are expensive to build and launch, so there’s a lot of planning that goes into choosing exactly what’s going to be shot into space. Space scientists and engineers recently went through the process of deciding on their science goals, so we thought we’d spend an episode explaining how this works, and how the next generation of spacecraft and telescopes will be selected.
Sep 13, 2010
Ep. 197: Astronomy Cast Live from Dragon*Con 2010
In this special live Dragon*Con 2010 episode of Astronomy Cast we welcomed special guest Les Johnson, Deputy Manager for NASA’s Advanced Concepts Office to talk about the state of human space exploration. And then we opened up the show to some amazing questions from the audience. Listen to the first live show ever done with both Fraser and Pamela in the same room.
Sep 06, 2010
Ep. 196: Luminosity and Magnitude
Astronomers measure the brightness of stars as magnitude. But this brightness depends on the distance to the star as well as the total amount of energy it's pumping out into space. And from our vantage point here on Earth, appearances can be deceiving.
Jun 28, 2010
Ep. 195: Planetary Rings
Saturn is best known for its rings. This huge and beautiful ring system is easy to spot in even the smallest backyard telescope, so you can imagine they were a surprise when Galileo first noticed them. But astronomers have gone on to find rings around the other gas giant worlds in the Solar System – the differences are surprising.
Jun 21, 2010
Ep. 194: Dwarf Planets
In 2006, the International Astronomical Union demoted Pluto out of the planet club. But they also started up a whole new dwarf planet club, with Pluto, Eris and the asteroid Ceres as charter members. Let’s find out what it takes to be a dwarf planet, and discuss the current membership.
Jun 14, 2010
Ep. 193: Astronomy with the Unaided Eye
We talk a lot about telescopes here on Astronomy Cast, but you really don't need any special equipment to appreciate what the night sky has to offer. Just head outside with some sky charts, maybe a planisphere, some friends and hot chocolate, and you're good to go. Let's talk about what kinds of things you can see with just your eyes.
Jun 07, 2010
Ep. 192: Chandra X-Ray Observatory
The Chandra X-Ray Observatory is the third of NASA's Great Observatories, sent into space aboard the space shuttle to view the Universe in high energy X-ray radiation. This is the territory of supernovae, supermassive black holes and neutron stars; some of the most extreme places in the Universe.
May 31, 2010
Ep. 191: Chandrasekhar
The first half of the 20th Century was a productive time for astronomy, with theorists working out much of the science that we take for granted today. One of these astronomy stars was Subrahmanyan Chandrasekhar, who determined the maximum mass of a white dwarf star.
May 24, 2010
Ep. 190: Kepler Mission
Last week we studied Kepler the man, and this week we take a look at Kepler, the mission. Launched in March, 2009, this is a spacecraft designed to search for Earth-like planets orbiting other stars. Let's take a look at the history this mission, the launch and the science gathered so far.
May 17, 2010
Ep. 189: Johannes Kepler and His Laws of Planetary Motion
Nicolaus Copernicus changed our understanding of the Universe when he rearranged the Solar System to put the Sun at the center, with the Earth becoming just another of the planets orbiting it. But the movement of the planets didn't really match the theory; not until Johannes Kepler came along with his ellipses, and everything finally worked.
May 10, 2010
Ep. 188: The Future of Astronomy
We spent 5 episodes telling the story of astronomy so far, how we got from the work of the Babylonians to the modern discoveries made in the last decade. But now we want to look forward, studying the current space missions and experiments to uncover the mysteries that astronomers hope to solve.
May 03, 2010
Ep. 187: History of Astronomy, Part 5: The 20th Century
Many of the modern ideas in astronomy happened in just the 20th century: dark matter, the Big Bang, inflation, quasars, black holes. So many discoveries in one important century.
Apr 26, 2010
Ep. 186: History of Astronomy, Part 4: The Beginning of Modern Astronomy
With our proper place in the Universe worked out, and some powerful telescopes to probe the cosmos, astronomers started making some real progress. The next few hundred years was a time of constant refinement, with astronomers discovering new planets, new moons, and developing new theories in astronomy and physics.
Apr 19, 2010
Ep. 185: History of Astronomy, Part 3: The Renaissance
Now we reach time with names that many of you will be familiar: Galileo, Kepler, Copernicus. This is an age when the biggest names in astronomy used the best tools of their time to completely rearrange their understanding of the Universe, putting the Earth where it belonged - merely orbiting the Sun, and not the center of everything.
Apr 12, 2010
Ep. 184: History of Astronomy, Part 2: The Greeks
With the earliest astronomers out of the way, we now move to one of the most productive eras in astronomy; the ancient Greeks. Even though they didn't have telescopes, the Greeks worked out the size and shape of the Earth, the distance to the Moon and Sun, and even had some accurate ideas about our place in the Universe.
Apr 05, 2010
Ep. 183: History of Astronomy, Part 1: The Ancient Astronomers
We know you love a good series. This time we're going to walk you through the history of astronomy, starting with the ancient astronomers and leading right up to the most recent discoveries. Today we're going to start at the beginning, with the astronomers who first tried to understand the true nature of the Earth, the planets and our place in the cosmos.
Mar 29, 2010
Ep. 182: Astrometry
Astronomers have been cataloging star positions for thousands of years, from the first calculations made by Hipparchus, to the more recent star catalogs made by the spacecraft named after him. This is astrometry; another way to find our place in the Universe.
Mar 22, 2010
Ep. 181: Rotation
Everything in the Universe is spinning. In fact, without this rotation, life on Earth wouldn't exist. We need the conservation of angular momentum to flatten out galaxies and solar systems, to make planets possible. Let's find out about the physics involved with everything that spins, and finally figure out the difference between centripetal and centrifugal force.
Mar 15, 2010
Ep. 180: Albedo
Why are some objects in the Solar System bright while others are dim? Much of an object's brightness is caused by its albedo, or how well it reflects radiation from the Sun. If you want to know how big a distant moon, comet, or asteroid is, you've got to know its albedo.
Mar 08, 2010
Ep. 179: Mysteries of the Universe, Part 2
Today we tackle more thrilling mysteries of the Universe. And by tackle, we mean, acknowledge their puzzling existence. Some mysteries will be solved shortly, others will likely trouble astronomers for centuries to come. Join us for part 2.
Mar 01, 2010
Ep. 178: Mysteries of the Universe, Part 1
All finished with the Milky Way, it's time to move on to the biggest mysteries of all. The mysteries of the Universe. Let's wonder about dark matter and dark energy, and the very nature of reality itself.
Feb 22, 2010
Ep. 177: Mysteries of the Milky Way, Part 2
We survived our first group of mysteries, so now we move onto our second set of stuff of amazing Milky Way mysteries. How many spiral arms does our galaxy have, and why does everything keep dying every 60 million years or so?
Feb 15, 2010
Ep. 176: Mysteries of the Milky Way, Part 1
We've wrapped up our Solar System mysteries and now we move onto the Milky Way mysteries, and the some of the general mysteries of galaxies. From blue stragglers to Eta Carinae... what's going on?
Feb 08, 2010
Ep. 175: Mysteries of the Solar System, Part 2
Apparently this is at least a 2 part series. This week we continue examining some of the baffling mysteries of the Solar System, where we fill your head with more questions than answers. Sometimes we've just got to share the enjoyment of not knowing the answer.
Feb 01, 2010
Ep. 174: Mysteries of the Solar System, Part 1
We know a lot about our Solar System, but there's an awful lot that's a complete and total mystery. Today we're going to begin a series of unknown length examining some of these mysteries, and explain the best theories astronomers have so far.
Jan 25, 2010
Ep. 173: Herschel Space Observatory
Last week we talked about Herschel the people – William Herschel, his sister Caroline, and his son John. This week we look at the Herschel Space Observatory, a mission launched in 2009 to reveal the coldest and dustiest regions in the Universe.
Jan 18, 2010
Ep. 172: William Herschel
Ancient astronomers knew of 5 planets, Mercury, Venus, Mars, Jupiter and Saturn - 6 if you count Earth. But then in 1781, William Herschel discovered an entirely new planet, boosting the number of planets to 7. Let's learn about Herschel, his equipment, his discoveries, and his sister Caroline - an accomplished astronomer of her own.
Jan 11, 2010
Ep. 171: Solar System Movements and Positions
Even in ancient times, astronomers realized there was something different about the planets - they move! The movement of the planets and their moons are governed by gravity. And as we all know, gravity can do some funny things.
Jan 04, 2010
Ep. 170: Coordinate Systems
This is going to be one of those weeks where we tackle something you're mentally avoiding. You know all those astronomical terms, like alt-azimuth, right ascension and declination, arc seconds and arc minutes? Of course not, your mind has blocked them out. Today we're going explain them, so you don't need to avoid them any more. Soon, you'll be ready to find anything in the cosmos.
Dec 28, 2009
Ep. 169: Fermi Mission
Last week we talked about Fermi the man, now we're going to talk about Fermi the space telescope. That's right, Enrico Fermi made such an impact in the astronomy and physics community that he got a space telescope named after him. Let's take a look at what this mission will do, and its discoveries so far.
Dec 21, 2009
Ep. 168: Enrico Fermi
Today's episode of Astronomy Cast is about another famous physicist: Enrico Fermi. We've already taken a look at one of Fermi's most famous ideas, the Fermi Paradox - or, where are all the aliens? But let's meet the man behind the ideas, the namesake for the new Fermi mission.
Dec 14, 2009
Ep. 167: Future Civilizations
Let's assume that humans survive the next few hundred years without destroying ourselves, or the planet, and we actually become a space faring civilization. What kinds of challenges will we face, and what projects will we build to expand ourselves out into the Solar System and eventually the galaxy. You just need to think big.
Dec 07, 2009
Ep. 166: Multiverses
What if our universe was just one in an infinite number of parallel universes; a possible outcome from the specific predictions of quantum mechanics. The idea of multiple universes is common in science fiction, but is there any actual science to back this theory up?
Nov 30, 2009
Ep. 165: Doppler Effect
You know how a police siren changes sound when it passes by you? That's the doppler effect. It works for sound waves and it works for light waves. Astronomers use the doppler effect to study the motion of objects across the Universe, from nearby extrasolar planets to the expansion of distant galaxies.
Nov 23, 2009
Ep. 164: Inside the Atom
We've talked about the biggest of the big, now let's focus in on the smallest of the small. Let's see what's inside that basic building block of matter: the atom. You probably know the basics, but with ever more powerful particle accelerators, physicists are revealing particles within particles, announcing new discoveries all the time.
Nov 16, 2009
Ep. 163: Auroras
When the Sun's solar winds crash into the Earth's magnetosphere, we get to enjoy an incredible light show called auroras, or the Northern and Southern Lights. Let's learn about what causes these incredible phenomena, and the best times and places that you can see them with your own eyes.
Nov 09, 2009
Ep. 162: Edwin Hubble
You might know the name "Hubble" because of the Hubble Space Telescope. But this phenomenal observatory was named after one of the most influential astronomers in modern history. Hubble discovered that galaxies are speeding away from us in all directions, leading to our current understanding of an expanding Universe. Let's learn about the man behind the telescope.
Nov 02, 2009
Ep. 161: Launch Facilities
Launching a rocket into space requires a big effort on the ground. Space agencies have built up huge infrastructures to store, prepare and launch rockets. Let's take a look at what's involved on the ground at a place like Cape Canaveral. What happens before, during and after a launch.
Oct 26, 2009
Ep. 160: Eclipses
Every now and then, the Moon destroys the Sun. Okay, not destroys, covers. Well, not really covers, but from here on Earth, sitting inside the shadow of the Moon, that's what it sure looks like. These events are called eclipses, or more precisely, transits and occultations. They occur whenever one object passes in front of another from a 3rd perspective. They're beautiful and exciting, and deliver a tremendous amount of science as well.
Oct 19, 2009
Ep. 159: Planet X
Astronomers have been searching for the mysterious Planet X for hundreds of years. It was the search for a theoretical planet beyond Uranus that turned up Neptune, and then again for Pluto. And even now there are some astronomers who think there's a more distant planet out there. Oh, and there are a bunch of pseudoscience cranks trying to freak people out about the end of the world. Don't worry, we'll make time for them too, but first let's start with some real science.
Oct 12, 2009
Ep. 158: Pulsars
Imagine an object with the mass of the Sun, crushed down to the size of Manhattan. Now set that object spinning hundreds of times a second, blasting out powerful beams of radiation like a lighthouse. That's a pulsar, one of the most exotic objects in the Universe.
Oct 05, 2009
Ep. 157: Constellations
Did you know there are 88 constellations in the night sky? Let's learn about the constellations and other star formations, their history, their connection to the zodiac, and how to find some of them.
Sep 28, 2009
Ep. 156: Famous Stars
This week we're going to talk about famous stars. But not those boring human ones you read about in People magazine. No, we're talking about those hot balls of plasma across the distant Universe. The close ones, the bright ones, the massive ones, the giant ones. Let's get to know some famous stars.
Sep 21, 2009
Ep. 155: Dwarf Stars
We think we live near an average star, but that's not the case at all. Compared to most stars in the Universe, the Sun is a giant! Let's look at the small end of the stellar spectrum, to stars with a fraction of the size and mass of our own Sun. There are many ways that a star can get small, and they lead dramatically different lives and deaths.
Sep 14, 2009
Ep. 154: Dragon*Con Live with Seth Shostak
This week we step away from our regular programming to bring you a live show from Dragon*Con in Atlanta. Pamela shares the stage with SETI researcher Seth Shostak. Together they discuss the technology and science of searching for intelligence, And answer questions from the audience.
Sep 07, 2009
Ep. 153: Dark Skies
If you live in a city, it's possible that you've never seen the Milky Way with your own eyes. To really appreciate everything the night skies have to offer, you've got to get out of the city, away from the lights, where the skies are really dark. But those places are getting harder and harder to find. Let's talk about what you can do to find dark skies, fight to make the skies darker, and how to make the most of wherever you live.
Aug 31, 2009
Ep. 152: Binary Stars
Did you know that our Solar System is a rarity with its single star. Astronomers believe that most star systems out there actually contain 2 or more stars – imagine seeing a sky with 4 suns. These binary and multiple star systems are a great target for new astronomers, and the dynamics of multiple stars keep astrophysicists busy too. Let's take a look at what it would be like to live on Tatooine.
Aug 24, 2009
Ep. 151: Atmospheres
Take a quick breath. There, that's what we're going to talk about today – the atmosphere. And not just the Earth's familiar atmosphere, but the strange, exotic and deadly atmospheres we find in the Solar System and surrounding extrasolar planets.
Aug 17, 2009
Ep. 150: Telescopes, the Next Level
We've explained how to get into astronomy and buy your first telescope. Now we're going to take things to the next level and get you drooling about bigger and better telescopes. If you're serious about astronomy, what kinds of telescopes will give you the best bang for big bucks?
Aug 10, 2009
Ep. 149: Constellation Program
It's been more than 40 years since humans first set foot on the Moon. But plans are in place to return humans to the surface of the Moon, and maybe even to asteroids and the planet Mars. New rockets, landers and flight technology are all under development. Humans are pushing out into space again, and this time we're going to stay. Let's take a look at NASA's new Constellation Program. What's been developed so far, and what's coming up.
Aug 03, 2009
Ep. 148: Astronomy and New Media
Astronomy is one of the scientific fields that have been completely shaken up by new media. The Internet has enabled communication between researchers in a dramatic new way, creating new collaborations, removing obstacles, and drawing in an army of enthusiastic volunteers to help with research. Let's take a look at how new media is helping change astronomy, and how you can get involved.
Jul 27, 2009
Ep. 147: How to Be Taken Seriously By Scientists
For those non-scientists trying to get their original ideas accepted by the scientific community, you've got to have thick skin. It might seem like there's a vast conspiracy, or a general attitude that drives away original, but unorthodox ideas. But that's not true, the reality is that great ideas in science come from everywhere, even amateurs. In this episode we'll help you understand what scientists will be looking for, and the best ways to be taken seriously.
Jul 20, 2009
Ep. 146: Astronomy Research from Idea to Publication
Have you ever wondered how astronomers do their research? How do they go from idea or question, to gathering their data, to publishing the research. What are all the hoops they have to jump through, the paperwork to fill out, and the cool toys they get to use along the way?
Jul 13, 2009
Ep. 145: Interstellar Travel
In science fiction it's easy to hop into your spaceship and blast off for other stars. But the true distances between stars, and the limits of relativity make interstellar travel almost impossible with our current technology. What would it really take to travel from star to star, exploring the galaxy?
Jul 06, 2009
Questions Show: Imaging Extrasolar Planets, Infinite Universe, Inside a Black Hole
What will we eventually be able to see on extrasolar planets? What does an infinite Universe mean? And what's down there, inside a black hole? If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show. Please include your location and a way to pronounce your name.
Jul 02, 2009
Ep. 144: Space Elevators
If you want to travel into the Solar System, you have to get off the Earth. Traditionally, that meant blasting off in a rocket. But there's another strategy for escaping the Earth's gravity. Climb to the top of an extremely tall tower, and just jump away. That's the idea behind space elevators. Theoretically possible, but practically unfeasible, space elevators have gotten new life thanks to new, super strong materials.
Jun 29, 2009
Questions Show: Matter Balance, Jumping Light Speed and Black Hole Star Formation
Why was there a difference between the amount of matter and antimatter at the beginning of the Universe? Mathematics lets us travel faster than light speed, so why can't we? And are there stars forming around black holes? If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show. Please include your location and a way to pronounce your name.
Jun 25, 2009
Ep. 143: Astrobiology
We know there's life in the Universe. We see it all around us here on Earth. But is there life anywhere else? By studying the extremes that life can take here on Earth, scientists are learning just how hardy and adaptable life can really be. And if you consider other ways that life might function, the options open up considerably. This week we'll discuss the study of life - extreme life here on Earth, and the possibility of finding life on other worlds.
Jun 22, 2009
Questions Show: Black black holes, Unbalancing the Earth, and Space Pollution
Why are black holes black? Can a huge mass of humanity make the Earth wobble? And what's so bad about space pollution anyway? If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show. Please include your location and a way to pronounce your name.
Jun 18, 2009
Ep. 142: Plate Tectonics
The surface of the Earth feels solid under your feet, but you're actually standing on a plate of the Earth's crust. And that plate is slowly shifting across the surface of the Earth. Over geologic timescales, plate tectonics has totally resurfaced our planet, bringing continents together, and tearing them apart. We know we have plate tectonics here on Earth, but what about other worlds?
Jun 15, 2009
Questions Show: Avoiding the Heat Death, Orbiting Galaxies, and the Dangers of Space Radiation
Will robots be able to avoid the heat death of the Universe? Can galaxies orbit each other like binary stars? And what are the dangers of space radiation to astronauts on the Moon? If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show. Please include your location and a way to pronounce your name.
Jun 11, 2009
Ep. 141: Volcanoes, Hot and Cold
You're familiar with volcanoes, eruptive vents where hot magma escapes the Earth's interior – sometimes with disastrous effects. But did you know that volcanoes have shaped many of the planets and moons in the Solar System, not just our own Earth? And just in the last few years astronomers have discovered there are cold volcanoes on some of the icy objects in the outer solar system.
Jun 08, 2009
Questions Show: Galileoscope, Black Hole Time, and What Exactly is Energy?
How can you get a Galileoscope of your very own? What happens to time inside a black hole? And what exactly is energy anyway? If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show. Please include your location and a way to pronounce your name.
Jun 04, 2009
Ep. 140: Entanglement
One of the most amazing aspects of quantum mechanics is quantum entanglement. This is the strange behavior where particles can become entangled, so they're somehow connected to one another – no matter the distance between them. Interact with one particle and the other reacts instantly; even if they're separated by billions of light-years.
Jun 01, 2009
Questions Show: Telescope Suggestions, Black Hole Energy, and Universal Time
What starting telescope equipment does the Astronomy Cast team suggest? How much energy does a black hole generate? And how do we measure time outside the Earth? If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show. Please include your location and a way to pronounce your name.
May 28, 2009
Ep. 139: Energy Levels and Spectra
Last week we took a peek into the tiny world of quantum mechanics, and its unintuitive, but very accurate mathematical predictions. And although we all appreciate the physics lesson, you're probably wondering what this all has to do with astronomy. Well, today we bring it all home and explain how quantum mechanics has given astronomers one of the most powerful tools they have to study the nature of the cosmos.
May 25, 2009
Questions Show: An Unlocked Moon, Energy Into Black Holes, and the Space Station's Orbit
What would happen if the Moon wasn't tidally locked to the Earth? What happens to all that mass and energy disappearing into a black hole? And how can we explain the space station's crazy orbit? If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show. Please include your location and a way to pronounce your name.
May 21, 2009
Ep. 138: Quantum Mechanics
Quantum mechanics is the study of the very tiny; the nature of reality at the smallest scale. It's a science that defies common sense, and delivers no helpful analogies. And yet it delivers the goods, making scientific predictions with incredible accuracy. Let's look into the history of quantum theory, and then struggle to comprehend its connection to the Universe.
May 18, 2009
Questions Show: Hidden Fusion, the Speed of Neutrinos, and Hawking Radiation
Are new stars dark until their photons reach the surface? How fast do neutrinos travel? And what’s the story with Hawking Radiation? If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show. Please include your location and a way to pronounce your name.
May 14, 2009
Ep. 137: Large Scale Structure of the Universe
This week we’re going to think big. Bigger than big. We’re going to consider the biggest things in the Universe. If you could pull way back, and examine regions of space billions of light-years across, what would you see? How is the Universe arranged at the largest scale? And more importantly… why?
May 11, 2009
Questions Show: The Source of Atmospheres, the Vanishing Moon, and a Glow After Sunset
How do planets get their atmospheres? What would happen to the Earth if the Moon just disappeared? And what’s that strange glow we see after sunset? If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show. Please include your location and a way to pronounce your name.
May 07, 2009
Ep. 136: Gamma Ray Astronomy
And now we reach the end of our tour through the electromagnetic spectrum. Last stop: gamma rays. These are the most energetic photons in the Universe, boosted up to incredible energies in the most violent places in the Universe. Gamma rays are tricky to catch, but they can reveal the most dramatic events in the Universe.
May 04, 2009
Questions Show: Dangerous Solar Flares, Higgs Boson Insights, and Light Speed Flashlights
Can our Sun generate a solar flare that would wipe out life on Earth? Has the Large Hadron Collider answered any questions about the Higgs boson? And what would happen if you shined your flashlight out the front window of a spaceship going almost the speed of light? If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show. Please include your location and a way to pronounce your name.
Apr 30, 2009
Ep. 135: X-Ray Astronomy
If you've ever broken a bone, X-rays are a part of the electromagnetic spectrum. Doctors use X-rays to study the human body, and astronomers use X-rays to study some of the hottest places in the Universe. So let's put on our X-ray specs, and see what we can see.
Apr 27, 2009
Questions Show: NorthEast Astronomy Forum (NEAF)
Pamela was lucky enough to attend the NorthEast Astronomy Forum, and while she was there she held a live questions show. And now you get to join in an hear the interesting questions, and Pamela's interesting answers. If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show. Please include your location and a way to pronounce your name.
Apr 23, 2009
Ep. 134: Ultraviolet Astronomy
Our next visit in this tour through the electromagnetic spectrum is the ultraviolet. You can't see it, but anyone who's spent a day out in the hot sun without sunblock has sure experienced its effects. Ultraviolet radiation is associated with the birth of stars and some of the hottest places in the Universe.
Apr 20, 2009
Ep. 133: Optical Astronomy
Optical astronomy; now this is the kind of astronomy a human being was born to do. In fact, until the last century, this was the only kind of astronomy anybody ever did. Now we've got the whole electromagnetic spectrum to explore, but our heart still belongs to optical astronomy. Of course, with bigger telescopes, better optics and more sensitive detectors, even optical astronomy has come a long way.
Apr 13, 2009
Questions Show: Undoing Inflation, Searching for Water, and Seeing Everything a Black Hole's Ever Eaten
If there was enough mass to cause a big crunch, would inflation go backwards too? How do spacecraft know that hydrogen is bonded to water? And why can't we see everything that's ever fallen into a black hole? If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show. Please include your location and a way to pronounce your name.
Apr 09, 2009
Ep. 132: Infrared Astronomy
Today we continue our unofficial tour through the electromagnetic spectrum, stopping at the infrared spectrum - you feel it as heat. This section of the spectrum gives us our only clear view through dusty material to see newly forming planetary systems and shrouded supermassive black holes. And infrared lets us look out to the most distant regions of the observable universe, when the first building blocks of galaxies came together.
Apr 06, 2009
Ep. 131: Submillimeter Astronomy
Last week we examined the largest wavelength in the electromagnetic spectrum: radio. This week we get a little smaller… but not too small! And look at the next step in the spectrum, the submillimeter. Astronomers have only recently began exploiting this tiny slice of the spectrum, but the payoff has been huge.
Mar 30, 2009
Questions Show: Decelerating Black Holes, Earth-Sun Tidal Lock, and the Crushing Gravity of Dark Matter
This week we wonder if you can made a black hole by accelerating a mass, but then can you un-make it again? Will the Earth ever be tidally locked to the Sun? And can dark matter crush an unsuspecting space ship? If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show. Please include your location and a way to pronounce your name.
Mar 26, 2009
Ep. 130: Radio Astronomy
Astronomers are very resourceful, when it comes to light, they use the whole spectrum - from radio to gamma rays. We see in visible light, but that's just a tiny portion of the spectrum. Today we're going to celebrate the other end of the spectrum; the radio end, where photons really stretch out their wavelengths.
Mar 23, 2009
Questions Show: Multiple Big Bangs, Satellite Collisions and the Size of the Universe
This week we wonder if the Universe is going to collapse and then expand again, how satellites can have such different velocities, and the size of the observable Universe. If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show. Please include your location and a way to pronounce your name.
Mar 12, 2009
Ep. 129: Interferometry
When it comes to telescopes, bigger is better. But bigger is more expensive. Way more expensive. To keep the costs reasonable while improving the sensitivity of their instruments, astronomers use an amazing technique called interferometry. Instead of building a single huge telescope, you can merge the light from several telescopes to act like a much larger telescope. It's a technique that has already revolutionized Earth-based observing - but just wait until it gets into space...
Mar 09, 2009
Questions Show: Shooting Lasers at the Moon and Losing Contact with Rovers
This week we find out how hard it is to hit the Moon with a laser, and if scientists lose contact with the Mars rovers when they go behind the Sun. If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show. Please include your location and a way to pronounce your name.
Mar 05, 2009
Ep. 128: Dust
You can't make a Solar System without a whole lot of dust. And that's the problem. This dust has blocked astronomers views into some of the most fascinating parts of the cosmos. It shields the galactic core, enshrouds newly forming stars and their planets, and blocks our view to churning supermassive black holes, actively feeding in distant galaxies. But new telescopes and techniques are allowing astronomers to peer through this dust, and see these events like never before.
Mar 02, 2009
Ep. 127: The US Space Shuttle
You’ve heard us talk about capsules, you’ve heard us talk about space suits, well today we take a look at the only currently in use reusable space craft. It’s a not a bird, its not a plane – It’s the US Space Shuttle. And to make it interesting – we’ve sent Scott Miller, Astronomy Cast student web developer, down to watch the launch so he can bring us back us first hand story.
Feb 16, 2009
Ep. 126: From Skeptics Guide with Questions
Orbiting black holes generate gravity waves. This week Bob Novella of Skeptics Guide to the Universe is going to pepper Pamela with questions, testing her ability to leap from tides to gravitational waves to Higgs bosons. We'll see where this takes us on this skeptical journey through what is known and what we're trying to learn about this universe.
Feb 09, 2009
Ep. 125: A Zoo of Extrasolar Planets
Dreaming up new planets is a favorite pastime of science fiction writers, but the universe often has them beat – coming with planets in place and forms that we had quite thought to imagine. Today we know of 228 stars orbiting alien stars, and in this episode we will look at the diversity of these worlds, from Mushy Lava covered planets to Icy Giants to the hottest of hot Jupiters.
Feb 02, 2009
Questions Show: Moons and the Drake Equation, Stars in the Void, and Rings Around Stars
This week we find out if moons around other planets could support life, if there's anything out there between galaxies, and whether stars form rings. If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show. Please include your location and a way to pronounce your name.
Jan 22, 2009
Ep. 124: Space Capsules, Part 1 - Vostok, Mercury and Gemini
The space capsule has been around for almost 50 years, when Yuri Gagarin headed to space in 1961. There have been many programs that used capsules by both the Americans and the Russians, and even the Chinese are using them now for their spaceflight program. Let's take a look at this rugged, dependable space vehicle that going to making a comeback in the next decade, when NASA sends humans back to the Moon.
Jan 19, 2009
Ep. 123: Homogeneity
As astronomers discovered that we live in a great big universe, they considered a fundamental question: is the universe the same everywhere? Imagine if gravity was stronger billions of light years away… Or in the past. It sounds like a simple question, but the answer has been tricky to unravel.
Jan 12, 2009
Ep. 122: How Old is the Universe
We did a wildly popular three part series about the center, size and shape of the Universe. But every good trilogy needs a 4th episode. This week we look at age of the Universe. How old is the Universe, and how do we know? And how has this number changed over time as astronomers have gotten better tools and techniques?
Jan 05, 2009
Questions Show: Questions Show: Stellar Roche Limits, Seeing Black Holes, and Water on Mars
This week we find out when stars get torn apart from gravity, how we can see supermassive black holes, how liquid water could have existed on Mars in the past, and much more. If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show. Please include your location and a way to pronounce your name.
Jan 01, 2009
Ep. 121: Spacesuits
As we've mentioned before, the Universe is trying to kill you. And for astronauts, that's truer than ever. One step out into the vacuum of space would be a world of hurt for an unprotected astronaut: the freezing cold temperature, the lack of atmospheric pressure, and the deadly radiation, just to name a few hazards. That's why the smart astronaut always puts on a spacesuit first. Let's take a look at the smallest spaceship around.
Dec 29, 2008
Ep. 120: The Christmas Star
With Christmas just around the corner, we thought we'd investigate a mystery that has puzzled historians for hundreds of years. In the bible, the birth of Jesus was announced by a bright star in the sky that led the three wise men to his birthplace. What are some possible astronomical objects that might look like such a bright star in the sky? And were there any unusual events that happened at that time?
Dec 22, 2008
Questions Show: Different Fields of Astronomy, Our Sibling Stars, and Hidden Lagrange Points
This week we find out the difference between an astronomer, an astrophysicist, and a cosmologist, the search for the stars that shared our nebula, hidden objects in Lagrange points, and much more. If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show. Please include your location and a way to pronounce your name.
Dec 18, 2008
Ep. 119: Robots in Space
Space is totally inhospitable. If the freezing temperatures don't get you, the intense radiation will kill you. Or the vacuum, or the lack of breathable atmosphere, or meteoroid impacts. Well… you get the idea. That's why most space exploration is done by hardy robots. They don't need to eat, drink or breathe. They get their energy from the Sun, and they've proven they've got the right stuff to explore every planet and major moon in the Solar System. Let's hear it for the space robots.
Dec 15, 2008
Questions Show: Distance in Space, Changing Earth's Orbit, and Different Sized Stars
This week we find out the distance between Betelgeuse and Bellatrex, how astronomers measure distance between objects, the possibility that an object could mess up the orbit of Earth, and the reason for different sizes of stars.
Dec 11, 2008
Ep. 118: Sky Surveys
In the old days, astronomers had to beg for telescope time. They'd put together a proposal, convince observatories to gather data for them, crunch that data and release the results. No telescope, no results. But everything's different now. Fleets of robotic telescopes constantly scan the skies, building up a vast database of raw data about the Universe. Anyone who wants can access the information through the Internet, download what they need to do real science. No telescope necessary. Let's look at the development of sky surveys, and how they're changing how astronomy gets done.
Dec 08, 2008
Ep. 117: Time
Today, time rules our lives. We live each day with the moments broken up into hours, minutes and seconds. We never seem to have enough time. But can you imagine not being able to tell time at all, where the movements of the Sun and the stars was the only way to know what time it was? Let's learn about the history of time, methods of telling time, and Einstein's historic discovery that time isn't as fixed as we thought it was.
Dec 01, 2008
Ep. 116: Molecules in Space
As part of her trip to England, Pamela had a chance to sit down with Oxford astrophysicist Chris Lintott and record an episode of Astronomy Cast. From the first stars to the newest planets, molecules and the chemistry that allows them to form affects all aspects of astronomy. While most astronomers group molecules into three bins of hydrogen, helium and everything else, there are a few who do proper chemistry by studying the sometimes complex molecules that form between the stars.
Nov 24, 2008
Ep. 115: The Moon, Part 3: Return to the Moon
It's time for a third lunar chapter. We've talked about the physical characteristics of the Moon, and the exploration. Now we're going to talk about the plans to return to the Moon. From the upcoming lunar reconnaissance orbiter to the plans to have humans set foot on the Moon again, for the first time in more than 50 years.
Nov 17, 2008
Questions Show: Spiral Arms, Seismic Waves on the Sun, and our Favorite Gear
This week we explore galactic spiral arms, seismic quakes on the Sun, and our picks for astronomy gear. If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show. Please include your location and a way to pronounce your name.
Nov 13, 2008
Ep. 114: The Moon, Part 2 - Exploration of the Moon
Let's continue on our journey to the Moon. Last week we talked about the physical characteristics of the Moon, its appearance in the sky and how it interacts with the Earth. This week we're going to take a look at how scientists have expanded our understanding of the Moon. From ancient astronomers using nothing more than their eyes and the first telescope observations of Galileo to the exploration by robotic spacecraft. And of course, the first tentative steps by the human explorers of the Apollo program.
Nov 10, 2008
Questions Show: Ice in Space, Expansion of the Universe, and Death from the Skies
Another week, another batch of questions. If ice disappears in your freezer, how can it last in space? How can the Universe be expanding faster than the speed of light? And what is the risk from a coronal mass ejection in an airplane? All this and even more questions. If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show. Please include your location and a way to pronounce your name.
Nov 06, 2008
Ep. 113: The Moon, Part 1
Hey, here's a topic we haven't gotten around to yet... the Moon. Today we look at our closest astronomical companion: the Moon. What impact does the moon have on our lives, where did it come from, who walked on it, and are we ever going to walk on it again? We're going to learn about the phases, the tides and even a little bit about NASA's plans to return to the Moon.
Nov 03, 2008
Questions Show: Orbit of the Planets, Green Stars, and Oort Cloud Contamination
We're back to a themeless questions show. We're right across the Universe this time. Why are the planets lined up in a nice flat plane? Why are there no green stars? And is the Oort Cloud contaminating our understanding of the cosmic microwave background radiation? If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show. Please include your location and a way to pronounce your name.
Oct 30, 2008
Ep. 112: Death from the Skies, Interview with Phil Plait
We say it all the time here on Astronomy Cast: the Universe is trying to kill us. This week, Pamela is joined by Dr. Phil Plait to discuss his new book, Death from the Skies. Phil and Pamela talk about asteroid strikes, solar flares and gamma ray bursts.
Oct 27, 2008
Questions Show: Relativity, Relativity and More Relativity
Everyone loves a theme. And this week we've collected together some of your questions about relativity. More light speed spacecraft, twin paradoxes, and the mixing up of gravity, time and mass. If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show. Please include your location and a way to pronounce your name.
Oct 23, 2008
Ep. 111: Nebulae
When you think about the best pictures in astronomy, almost every one is a nebula; the pillars of creation in the Eagle Nebula, or the complex Helix Nebula - or my personal favorite, the Ring Nebula. They're beautiful, wispy clouds of gas and dust that signify both the birth and death of stars. Today we give tribute to nebulae.
Oct 20, 2008
Questions Show: Galactic Dust, the Speed of Photons, and the Big Bang Calculations
Another week, another roundup of your questions. This week listeners asked: what is galactic dust anyway, and where does it come from? Why can photons move at the speed of light? And how can astronomers know what happened right after the Big Bang? And there's even more. If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show. Please include your location and a way to pronounce your name.
Oct 19, 2008
Ep. 110: The Search for Extraterrestrial Intelligence
You know what this show needs? More aliens. Since we don't seem to have any visiting right now, we're going to have to find some. SETI is an acronym. It stands for the Search for Extraterrestrial Intelligence. But there's more to SETI than just putting up a radio telescope and hoping to catch a glimpse of an alien television broadcast.
Oct 13, 2008
Questions Show - Alignment with the Galactic Plane, Destruction from Venus, and the Death of the Solar System
Another week, another roundup of your questions. This week listeners asked: are we all going to die in 2012 when the solar system passes through the galactic plane? Did Venus make the Moon? And what will extraterrestrials see when the Sun is dead and gone? And there's even more. If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show.
Oct 09, 2008
Ep. 109: The Life of Other Stars
Last week we looked at the complete life of the Sun, birth to death. But stars can be smaller, and stars can get much much larger. And with a change in mass, their lives change too. Let's start the clock again, and see what happens to the smallest stars in the Universe; and what happens to the largest.
Oct 06, 2008
Questions Show - Running Out of Gravitons and Hitting the Brakes at Light Speed
Another week, another roundup of your questions. This week listeners asked: if forces are communicated through particles, can we run out? If you were traveling at light speed, when would you know to stop? And there's even more. If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show.
Oct 02, 2008
Ep. 108: The Life of the Sun
We've talked about the Sun before, but this time we're going to look at the entire life cycle of the Sun, and all the stages it's going to go through: solar nebula, protostar, main sequence, red giant, white dwarf, and more. Want to know what the future holds for the Sun, get ready for the grim details.
Sep 29, 2008
Questions Show - light speed, Andromeda galaxy, dark matter and black holes
Another week, another roundup of your questions. This week listeners asked: will reaching light speed destroy the Universe? When is Andromeda going to look really, really cool with the unaided eye? Why didn't dark matter all turn into black holes? And there's even more. If you've got a question for the Astronomy Cast team, please email it in to and we'll try to tackle it for a future show.
Sep 26, 2008
Ep. 107: Nucleosynthesis: Elements from Stars
Look around you. Breathe in some air. Everything you can see and feel was formed in a star. Today we'll examine that long journey that matter has gone through, forged and re-forged in the hearts of stars. In fact, the device you're using to listen to this podcast has some elements formed in a supernova explosion.
Sep 22, 2008
Questions Show - Black Hole Surfaces, Magnetic Field Strengths, and the Speed of Gravitons
As you know, we wanted to answer listener questions regularly, but we found it was taking away from the regular weekly episodes of Astronomy Cast. So we've decided to just split it up and run the question shows separately from the regular Astronomy Cast episodes. If this works out, you might be able to enjoy twice the number of Astronomy Cast episodes. So if you've got a question on a topic we cover in a recent show, or you just have a general astronomy question, send it in to Either by email, or record your question and email in the audio file.
Sep 18, 2008
Ep. 106: The Search for the Theory of Everything
At the earliest moments of the Universe, there were no separate forces, energy or matter. It was all just the same stuff. And then the different forces froze out, differentiating into electromagnetism, the strong force and the weak force. Today we'll look at the problem that has puzzled physicists for generations: is there a single equation that explains all the forces we see in the Universe. Is there a theory of everything?
Sep 15, 2008
Student Questions Show: Leelanau School
This is our forth installment in our series of student questions shows and these questions come to us from Leelanau High School.
Sep 14, 2008
Ep. 105: The Strong and Weak Nuclear Forces
After a quick Dragon*Con break, we're back to our tour through the fundamental forces of the Universe. We've covered gravity and electromagnetism, and now we're moving onto the strong and weak nuclear forces. We didn't think they'd really need to be separate episodes, so we're putting them together. And then we'll cap the whole series with the quest for the theory of everything.
Sep 08, 2008
Ep. 104: Science Fiction at Dragon*Con with Plait and Grazier
Pamela left Fraser behind (with sorrow) and took on Dragon*Con and the facts (or lack there of) in Science Fiction. Helping her out were special guests Phil Plait and Kevin Grazier.
Sep 01, 2008
Ep. 103: Electromagnetism
Our series on the basic forces of the cosmos continues! Last week we discussed gravity, and this we'll handle electromagnetism. Electricity and magnetism are just two aspects of the same force, and you can't talk about astronomy without understanding these two keys aspects of physics.
Aug 25, 2008
Ep. 102: Gravity
You seem to like a nice series, so here's a new one we've been thinking about. Over the course of the next 4 weeks, we're going to cover each of the basic forces in the Universe. And this week, we're going to start with gravity; the force you're most familiar with. Gravity happens when masses attract one another, and we can calculate its effect with exquisite precision. But you might be surprised to know that scientists have no idea why gravity happens.
Aug 18, 2008
Ep. 101: Advanced Propulsion Systems
Last week we talked about rockets. How they work and their limitations. This week we're going to look at the future of propulsion systems. From the ion engines that are already working to explore the Solar System to the prototype solar sails to futuristic technologies like magnetic sails, and bussard ramjets. This is how we'll travel to other stars.
Aug 11, 2008
Ep. 100: Rockets
To move around in space, you need some kind of propulsion system. And for now, that means rockets. Let's learn the underlying science of rockets, and how they work. And learn why a rocket will never let us reach the speed of light.
Aug 04, 2008
Ep. 99: The Milky Way
The Milky Way is our home. An island of stars in a universe of other galaxies. But you might be surprised to learn that astronomers have only known the Milky Way's true nature for just a century. Let's learn the history of discoveries about the Milky Way, and what today's science tells us. And let's peer into the future to learn the ultimate fate of our galaxy.
Jul 28, 2008
Ep. 98: Quasars
Last week we talked about galaxies in general, and hinted at the most violent and energetic ones out there: active galaxies. Quasars have been a mystery for half a century; what kind of object could throw out more radiation than an entire galaxy? A black hole, it turns out, with the mass of hundreds of millions of suns performs this feat. Let's trace back the history of quasars, how they were first discovered and puzzled astronomers for so long. And let's look at what we know today.
Jul 21, 2008
Ep. 97: Galaxies
This week we're going to look at some of the biggest objects in the Universe: galaxies. It was the discovery of galaxies in the early 20th century that helped astronomers realize just how big the Universe is, and how far away everything is. Let's learn how galaxies formed and how they evolve and change over time, merging with the neighbors. And what the future holds.
Jul 14, 2008
Ep. 96: Humans to Mars, Part 3 - Terraforming Mars
And now we reach the third part of our trilogy on the human exploration and colonization of Mars. Humans will inevitably tire of living underground, and will want to stretch their legs, and fill their lungs with fresh air. One day, we'll contemplate the possibility of reshaping Mars to suit human life. Is it even possible? What technologies would be used, and what's the best we can hope for?
Jul 07, 2008
Ep. 95: Humans to Mars, Part 2 - Colonists
After astronauts make the first tentative steps onto the surface of Mars, a big goal will be colonization of the Red Planet. The first trailblazers who try to live on Mars will have their work cut out for them, being in an environment totally hostile to life. What challenges will they face, and how might they overcome them?
Jun 30, 2008
Ep. 94: Humans to Mars, Part 1 - The Scientists
We're learned about the failed missions to Mars in the past, and the current spacecraft, rovers and landers currently exploring the Red Planet. But the real prize will come when the first human sets foot on Mars. Robots are cheaper, but nothing beats having a real human being on the scene, to search for evidence of water and life.
Jun 23, 2008
Ep. 93: Missions to Mars, Part 2
I know last week was a bit of a dry history lesson, but we wanted to give you some understanding of past efforts to explore Mars. Now we'll look at the missions currently in orbit, and crawling around the surface of Mars, and help you understand the science that's happening right now.
Jun 16, 2008
Ep. 92: Missions to Mars, Part 1
With last month's safe arrival of the Phoenix Mars Lander, Mars enthusiasts breathed a collective sigh of relief… phew. Now it's time to search for evidence of organic molecules in the ice at Mars' north pole. But this is just the latest in a long series of missions sent to the Red Planet. Let's have a history lesson, and look back at the missions sent to Mars, successful and unsuccessful.
Jun 09, 2008
Ep. 91: The Search for Water on Mars
With the successful touchdown of the Phoenix Lander, NASA is continuing its quest to find evidence of past and present water on Mars. This week we discuss the geologic history of Mars, and explain why NASA thinks the story of water on Mars is so important. And how this ties into the search for life on the Red Planet.
Jun 02, 2008
Ep. 90: The Scientific Method
You've heard us say it 90 times: "How we know what we know." But how do we know how we know what we know? So astronomers like all scientists use the scientific method. Without the scientific method we'd probably still think the Earth is flat, only a few thousand years old and the center of the universe. But with the scientific method everything changes. From biology, to chemistry, to physics, to astronomy it is impossible to count the number of changes that have happened to human society because of changes brought about from the scientific method. In this episode we tell you about what the scientific method is, how you can use it to improve your life, and discuss why gravity isn't just a theory.
May 26, 2008
Ep. 89: Adaptive Optics
Since the dawn of humanity, astronomers have wished to destroy the atmosphere. Oh sure, it's what we breathe and all, but that stupid atmosphere is always getting in the way. Since destroying the atmosphere is out of the question, astronomers have figured out how to work with it. To distort the mirror of the telescope itself though the magic of adaptive optics.
May 19, 2008
Ep. 88: The Hubble Space Telescope
Our understanding of the cosmos has been revolutionized by the Hubble Space Telescope. The breathtaking familiar photos, like the Pillars of Creation, pale in comparison to the astounding amount of science data returned to Earth. Hubble's getting old, though, serviced several times already, and due for another mission later this year. Let's relive the historic observatory's amazing life so far, and see what the future holds.
May 12, 2008
Ep. 87: The End of the Universe Part 2: The End of Everything
Hopefully you've all recovered from part 1 of this set, where we make you sad about the future of the humanity, the Earth, the Sun and the Solar System. But hang on, we're really going to bring you down. Today we'll look far far forward into the distant future of the Universe, at timescales that we can barely comprehend.
May 05, 2008
Ep. 86: The End of the Universe Part 1: The End of the Solar System
This is a show we wanted to do since we started Astronomy Cast but we always thought it was too early. We wanted you to know that we're positive, happy people with enthusiasm for astronomy and the future. It's time for some sadness. It's time for a grim look to see what the future holds for the Universe. This week we stay close to home and consider the end of humanity, the Earth, the Sun, and the entire Solar System. Next week we'll extend out to the very end of the Universe.
Apr 28, 2008
Ep. 85: Detectors
Our senses can only detect a fraction of the phenomena happening in the Universe. That's why scientists and engineers develop detectors, to let us see radiation and particles that we could never detect with our eyes and ears. This week we'll go through them all, so you can understand how we see what we can't see.
Apr 21, 2008
Ep. 84: Getting Around the Solar System
Have you ever wondered what it takes to get a spacecraft off the Earth and into space. And how managers at NASA can actually navigate a spacecraft to another planet? And how does a gravity assist work? And how do they get them into orbit? And how do they land? So many questions…
Apr 14, 2008
Ep. 83: Wave Particle Duality
Have you ever heard that photons behave like both a particle and a wave and wondered what that meant? It's true. Sometimes light acts like a wave, and other times it behaves like a little particle. It's both. This week we discuss the experiments that demonstrate this, explain how scientists figured it all out in the first place. What does wave/particle duality have to do with astronomy? Well, everything, since light is the only way astronomers can see out into the Universe.
Apr 07, 2008
Ep. 82: Space Junk
We're polluting every corner of our own planet, so it only makes sense that we'll take our trashy habits out into space with us. This week we look at the myriad of ways we're messing up space, from the trash orbiting the planet to the radiation we're leaking out into space.
Mar 31, 2008
Ep. 81: Questions on the Shape Size and Centre of the Universe
As predicted we got a lot of questions from people about our trilogy of shows on the size, shape and centre of the universe. Today we'll do our best to clear them all up.As always, if you're still confused drop us an email to info at astronomycast dot com.
Mar 24, 2008
Ep. 80: Craters
Pamela's attending the 39th Lunar and Planetary Sciences Conference, and you know what that means: the Moon… and planets! When you think of the Moon, you think of craters. In fact, that's a big theme this week at the conference, so Pamela took it as inspiration. Here you go, the week we drove the show into a crater. Wait… there's got to be a better way to describe this.
Mar 17, 2008
Ep. 79: How Big is the Universe?
We’re ready to complete our trilogy of discovery about the universe. We’ve learned that it has no center; rather everywhere is its center and nowhere. We discovered that the universe seems to be flat. It not open, it is not closed, it is flat. If that doesn’t make any sense, you need to listen to the previous show because there’s no way I could give that an explanation. So now we want to know: “How big is it?” Does it go on forever or is it finite in scale? How much of it can we see?
Mar 10, 2008
Ep. 78: What is the Shape of the Universe?
Some of the biggest questions in the universe depend on its shape. Is it curved? Is it flat? Is it open? Those may not make that much sense to you, but in fact it’s very important for astronomers. So which is it? How do we know? How did we figure it out? Why does it matter?
Mar 03, 2008
Ep. 77: Where is the Centre of the Universe?
There are some people – I’m not naming names – who think the universe revolves around them. In fact, for most of humankind, everybody thought that. It’s only been in the last few hundred years that scientists finally puzzled out that the Earth isn’t the centre of the universe at all. That begs the question: where is the centre?
Feb 25, 2008
Ep. 76: Lagrange Points
Gravity is always pulling you down, but there are places in the solar system where gravity balances out. These are called Lagrange points and space agencies use them as stable places to put spacecraft. Nature is on to them and has already been using them for billions of years.
Feb 18, 2008
Student Questions: Curtis High School
This is our second installment in our series of student questions shows and these questions come to us from Curtis High School.
Feb 16, 2008
Ep. 75: Stellar Populations
After the big bang, all we had was hydrogen, a little bit of helium, and a few other trace elements. Today, we’ve a whole periodic table of elements to enjoy, from oxygen we breathe to the aluminium cans we drink from to the uranium that powers some people’s homes. How did we get from plain old hydrogen to our current diversity? It came from stars, in fact successive generations of stars.
Feb 11, 2008
Ep. 74: Antimatter
Sometimes, we don’t get to decide what our show’s about. So many threads come together at the same time driving the decision for us. This is one of those situations. We’ve gotten so many questions from listeners in just the last week about antimatter that our show had just been chosen for it. You command, we obey. Let’s talk about antimatter.
Feb 04, 2008
Ep. 73: Questions Show #8
We’ve been so crazy following our own whims through the universe that we’ve neglected your questions. That ends today. It’s time to dig deep into our overflowing email box to retrieve the puzzling questions our listeners have sent in.
Jan 28, 2008
Ep. 72: Cosmic Rays
We’re going to return back to a long series of episodes we like to call: Radiation that Will Turn You Into a Superhero. This time we’re going to look at cosmic rays, which everyone knows made the Fantastic Four. These high-energy particles are streaming from the Sun and even intergalactic space, and do a wonderful job of destroying our DNA, giving us radiation sickness, and maybe (hopefully!) turning us into superheroes.
Jan 21, 2008
Ep. 71: Gravitational Waves
When he put together his theories of relativity, Einstein made a series of predictions. Some were confirmed just a few years later, but scientists are still working to confirm others. And one of the most fascinating is the concept of gravitational waves. As massive objects move in space, they send out ripples across the Universe that actually distort the shape of matter. Experiments are in place and in the works to detect these gravitational waves as they sweep past the Earth.
Jan 14, 2008
Ep. 70: How to Win a Nobel Prize
Just a couple of shows ago, we showed you how to get a career in astronomy. Now that you've got your career in astronomy, obviously the next goal is to win a Nobel prize. We're here at the American Astronomical Society meeting in Austin, which is just one tiny step that a person has to take before you get that Nobel prize. Before you get that call in the middle of the night from Sweden, you're going to need to come with an idea, do some experiments, write a paper, get published and a bunch of other stuff. This week, we'll tell you all about it.
Jan 07, 2008
Student Questions: Farmersburg School
Thanks to GLAST, Astronomy Cast is now able to provide equipment to send to high school teachers who want to Pamela and Fraser to do a special questions show just for their class. We will be making this shows available on the feed on days other than Monday (that's still reserved for your regularly scheduled Astronomy Cast). This is the first one available and comes with questions from Farmersburg School.
Jan 06, 2008
Episode 69: The Large Hadron Collider and the Search for the Higgs-Boson
When it was first developed, the standard model predicted a collection of particles, and thanks to more and more powerful colliders, physicsists have been able to find them all except one: the Higgs-Boson. It's an important one because it should explain how objects have mass. The European Large Hadron Collider should have the power and sensitivity to find the Higgs-Boson.
Dec 31, 2007
Episode 68: Globular Clusters
This week we're going to study some of the most ancient objects in the entire Universe; globular clusters. These relics of the early Universe contain hundreds of thousands of stars, held together by their mutual gravity. Since they formed together, they give astronomers a unique way to test various theories of stellar evolution.
Dec 24, 2007
Episode 67: Building a Career in Astronomy
With all the enthusiasm that’s being generated with astronomy, it’s had a bit of a strange side-effect. We’ve been causing some of our listeners to have midlife crises about their careers. We’ve had other people who just want advice – they’re moving into college for the first time and they want to direct the courses they’re going to be taking into astronomy. Some other people already have skills that are very useful and have wondered how they can help up or even change their career to be working in the field. We thought we’d try and answer everyone’s questions all at once and just run through the major career paths you can take that relate to astronomy and space, and the kinds of things you’ll need to do to actually make yourself a good candidate for that field.
Dec 17, 2007
Episode 66: How Amateurs can contribute to Astronomy
Astronomy is one of the few sciences where amateurs make meaningful contributions to discoveries. Many professional researchers work hand-in-hand with teams of amateurs to make discoveries that just wouldn't be possible without this kind of collaboration. In fact, Pamela regularly relies on dedicated enthusiasts for her data on variable stars.
Dec 10, 2007
Episode 65: The End of Our Tour Through the Solar System
All good things come to an end - we now find ourselves in the outer reaches of the solar system where our Sun is hard to distinguish from the other bright stars in the sky. But we're not done with the solar system, there's some stuff that's leftover. This week, we look at the outer reaches of the solar system and how it interacts with the rest of the universe.
Dec 03, 2007
Episode 64: Pluto and the Icy Outer Solar System
It's been a long journey, 64 episodes, but now we're back where we began: Pluto. Last time we talked about how Pluto lost its planethood status, so we won't go over all that again. This time we're going to talk about Pluto, its moons, the Kuiper belt, and the other icy objects that inhabit the outer Solar System.
Nov 26, 2007
Episode 63: Neptune
We’ve reached Neptune, the final planet in our tour through the solar system – but don’t worry! The tour’s not over, but after this week we’ll be all out of planets. Neptune has a controversial story about its discovery, some of the strongest winds in the solar system and some weird moons.
Nov 19, 2007
Episode 62: Uranus
This week, we're on to the next planet in the solar system. We don't know a whole lot about this blue gas planet, but today we'll cover some of the neat stuff we do know, including it's faint rings, sideways axis of rotation and its rocky core - a first in the gas planets we've encountered so far in our tour.
Nov 12, 2007
Episode 61: Saturn's Moons
We know that delaying this show one more week would be too dangerous, so here you go: Saturn's moons. These are some of the most interesting objects in the Solar System, from the spongy Hyperion, to the geysers on Enceladus, to the rainy, misty, oceany Titan. They've kept Cassini busy for years, and scientists will likely be pondering them for decades.
Nov 05, 2007
Episode 60: Questions on Inflation
It's about time for a question show again, so we'll have one last interruption to our planetary tour, to deal with the questions that arose from our inflation show.So if you still don’t understand inflation, take a listen to this week's show and as always, send us your questions.
Oct 29, 2007
Episode 59: Saturn
Returning to our journey through the solar system, let's voyage away from the largest planet to the second largest, Saturn. Once again, we'll break up our visit because there's lots to talk about. This week, we talk about Saturn and its famous rings. Next week, we'll discuss its many moons.
Oct 22, 2007
Episode 58: Inflation
We interrupt this tour through the solar system to bring you a special show to deal with one of our most complicated subjects: the big bang. Specifically, how it's possible that the universe could have expanded faster than the speed of light. The theory is called the inflationary theory, and the evidence is mounting to support it. Einstein said that nothing can move faster than the speed of light, and yet astronomers think the universe expanded from a microscopic spec to become larger than the solar system, in a fraction of a second.
Oct 15, 2007
Episode 57: Jupiter's Moons
Last week we talked about Jupiter and we could sense right away it would be too much to handle. This week, we'll talk about Jupiter's moons - how many are there? What makes them so interesting? Is it true that the most likely place in the solar system to find life (other than Earth) is actually on one of Jupiter's moons? Hang on tight. We're going to cover a lot.
Oct 08, 2007
Episode 56: Jupiter
Last week we talked about rubble, this week we're going to dig into the largest planet in the Solar System: Jupiter, but will it all just be hot gas? There's so much to talk about, we've decided to break this up into two shows. This week we're going to just talk about Jupiter, and then next week, we're going to cover its moons.
Oct 01, 2007
Episode 55: The Asteroid Belt
In the last few weeks we've had many emails saying that our tour of the solar system would not be complete without a show on the asteroid belt. Your wish is our command! We talked about Mars in episode 52, and now that we're back on track our next stop is the asteroid belt.
Sep 24, 2007
Episode 54: Questions Show #6
It's been a while, so let's catch up with the listener questions. We've got some easy ones, some hard ones and probably some impossible ones. We talk about our universe as a black hole, tidal locking of planets like Uranus, colours of stars at different ages, our universe's birthday and more.
Sep 17, 2007
Episode 53: Astronomy in Science Fiction
This is a very different episode of Astronomy Cast. As we mentioned last week, Pamela recently attended the Dragon*Con science fiction convention in Atlanta, Georgia. While she was there, she participated in a special live edition of Astronomy Cast with special guest Dr. Kevin Frazier. Kevin is a NASA scientist, and the science consultant for the TV shows Battlestar Galactica and Eureka. He and Pamela work through physics and astronomy in popular science fiction. What they get right, and what they get wrong... so very wrong.
Sep 10, 2007
Special Episode: Panspermia
As a reward to the all the dedicated fans who completed our demographic survey, we released this special episode of Astronomy Cast. As promised, we're now releasing this episode to all of our subscribers. Panspermia is a controversial theory that life on Earth originated… out there. Maybe it started out in a cosmic dust cloud or originated from another planet, but somehow the very first lifeforms made the trip through the vacuum of space and colonized our home planet.
Sep 04, 2007
Episode 52: Mars
Today we consider Mars, the next planet in our journey through the Solar System. Apart from the Earth, it's the most explored planet in our Solar System. Even now there are rovers crawling the surface, orbiters overhead, and a lander on its way. It's a cold, dry desert, so why does this planet hold such fascination?
Sep 03, 2007
Episode 51: Earth
So, another week, another planet. Last week we discussed Venus, and that means this week it is time for our home planet - Earth.
Aug 27, 2007
Episode 50: Venus
Last week we talked about Mercury, so this week our planetary parade proceeds to Venus. It's the brightest object in the sky, the hottest object in the solar system, and it's probably one of the most deadly places to go and visit.
Aug 20, 2007
Episode 49: Mercury
We're still digging through the thousands of comments and suggestions from the listener survey but we hear your requests and suggestions, and now you get to start reaping the benefits. Today we start our survey of the solar system with Mercury. What mysteries is it hiding from us? How similar is Mercury to the other rocky planets? How much do we really know about this first rock from the Sun?
Aug 13, 2007
Episode 48: Tidal Forces Across the Universe
Last week we talked about tidal forces within our solar system. This week we're going to expand our view and encompass the entire universe. Some of the most dramatic events originate from tidal forces caused by gravity: other worlds, galaxies, black holes and even entire clusters of galaxies are under this influence.
Aug 06, 2007
Episode 47: Tidal Forces
Consider the following: we've got tides here on Earth, the Moon only shows one face to the Earth, we've got volcanoes on Io, and ice geysers on Enceladus. All these phenomena originate from a common cause: the force of gravity stretching across space to tug at another world.
Jul 30, 2007
Episode 46: Stellar Nurseries
We've discussed star formation in the past, but now we wanted to talk about the different kinds of stellar nurseries we see across the Universe. We know where our Sun came from because we can look out and see different stellar neighborhoods at every stage of development. It takes a village of gas and dust to raise a star.
Jul 23, 2007
Episode 45: The Important Numbers in the Universe
This week we wanted to give you a basic physics lesson. This isn't easy physics, this is a lesson on the basic numbers of the Universe. Each of these numbers define a key aspect of our Universe. If they had different values, the Universe would be a changed place, and life here on Earth would never have arisen.
Jul 16, 2007
Episode 44: Einstein's Theory of General Relativity
If you remember way back to Episode 9, we covered Einstein's Theory of Special Relativity. Well, that's only half of the relativity picture. The great scientist made an even more profound impact on physics with his theory of general relativity, replacing Newton with a better model for gravity.
Jul 09, 2007
Episode 43: Questions, Questions #5
It's time to answer the questions again. And this time we've got some doozies. Is the Universe rotating? Is space something, or is it nothing? Is dark energy evenly distributed? What would happen if an astronaut went out the airlock, without a spacesuit. Want to know the answers? Well, you've got to listen.
Jul 02, 2007
Episode 42: Magnetism Everywhere
You probably don't realise it, but magnetic fields are everywhere. We're not talking about the magnets in your speakers, your electronic equipment or on the fridge door. We're talking about the gigantic magnetic fields that surround planets, stars, galaxies and some of the most exotic objects in the Universe.
Jun 25, 2007
Episode 41: The Rise of the Supertelescopes
The last decade has been the golden age of astronomy, with new observatories and space telescopes pushing out our understanding of the Universe. We can see billions of light years away, watch dynamic events unfold in almost real-time, and see into every corner of the electromagnetic spectrum. Just you wait: things will only get better. Here come the supertelescopes!
Jun 18, 2007
Episode 40: American Astronomical Society Meeting, May 2007
Once again, Pamela does her duty as an astronomer and joins her colleagues at the American Astronomical Society's meeting, held in May, 2007 on Honolulu, Hawaii. With all that sand, surf and sun, how did anyone get any science done? Pamela tracked down the interesting stories, and brought them back so we could analyze them.
Jun 11, 2007
Episode 39: Astrology and UFOs
While Pamela's away at the American Astronomical Society meeting, we brought in a special guest to help debunk some of the pseudoscience that people mistake for astronomy. Dr Steven Novella from the Skeptic's Guide to the Universe gets to the bottom of astrology and UFOs, and why they're not real science.
Jun 04, 2007
Episode 38: Neutron Stars and their Exotic Cousins
Huge stars become black holes, and small stars become white dwarfs. But medium-sized stars can become neutron stars; exotic objects that overcome the nuclear force holding protons and electrons apart. What was once the size of a star is compressed down to only a few dozen kilometres across.
May 28, 2007
Episode 37: Gravitational Lensing
Astronomers are always trying to get their hands on bigger and more powerful telescopes. But the most powerful telescopes in the Universe are completely natural, and the size of a galaxy cluster. When you use the gravity of a galaxy as a lens, you can peer right back to the edges of the observable Universe.
May 21, 2007
Episode 36: Gamma-Ray Bursts
Gamma ray bursts are the most powerful explosions in the Universe, releasing more energy in a few seconds than our Sun will put out in its lifetime. It's only been in the last few years that astronomers are finally starting to unravel the cataclysmic events that cause these energetic explosions.
May 14, 2007
Episode 35: Questions Show #4
We know there's matter, and we know there's anti-matter. If there's dark matter, is there an anti-dark matter? How come gravity can escape from a black hole? Do black holes capture dark matter? Can a moon have a moon? Can a planet have two stars? If you've had any of these questions, you'll want to listen to this week's show.
May 07, 2007
Episode 34: Discovering Another Earth
What a week! Astronomers announced the discovery of an Earth-sized planet orbiting the nearby star Gliese 581. We talk about the technique used to discover the planet, the possibilities of finding even smaller planets, and what the future holds for finding another Earth.
Apr 30, 2007
Episode 33: Choosing and Using a Telescope
Buying your first telescope can be a nerve-wracking experience filled with buyer's remorse. This week we discuss the basics of purchasing your first binoculars and telescope. What to look for, how to clean older equipment, and how to use it for the first time. Let's make sure your first investment in this wonderful hobby is money well-spent.
Apr 23, 2007
Episode 32: The Search for Neutrinos
Trillions of neutrinos are produced in our Sun through its nuclear reactions. These particles stream out at nearly the speed of light, and pass right through any matter they encounter. In fact, there are billions of them passing through your body right now. Learn how this elusive particle was first theorized and finally discovered.
Apr 16, 2007
Episode 31: String Theory, Time Travel, White Holes, Warp Speed, Multiple Dimensions, and Before the Big Bang
We get questions every week about string theory and topics popularized by science fiction. Here's the problem. There's just no evidence. Each of these is based on wonderful and well-formed mathematical equations, or wishful thinking, but they're very hard (if not impossible) to test in the real Universe.
Apr 09, 2007
Episode 30: The Sun, Spots and All
It's Spring in the Northern Hemisphere, and that means the Sun is back. But it's more than just a free heat lamp for your garden, it's an incredible, dynamic nuclear reaction complete with flares, coronal mass ejections, twisting magnetic fields and the solar wind. Put in your headphones, head outside and enjoy the sunshine while you listen to this week's podcast.
Apr 02, 2007
Episode 29: Asteroids Make Bad Neighbors
This week we're talking about asteroids. And not just any asteroids, but Near Earth Objects. How do astronomers find these things, why are they buzzing around the Earth, what are the chances we'll actually get hit, and what would happen if we did get hit? How could we stop them?
Mar 26, 2007
Episode 28: What is the Universe Expanding Into?
Come on, admit it, you've had this question. If the Universe is expanding from the Big Bang, what is it expanding into? What's outside the Universe? Ask any astronomer and you'll get an unsatisfying answer. We give you the same unsatisfying answer, but really explain it, so your unsatisfaction doesn't haunt you any more.
Mar 19, 2007
Episode 27: The Third Question Show
The questions are piling up, so it's time to get through them. We've got a great collection this week. How can our eyes collect so many photons? What's the speed of gravity? Shouldn't the light from the cosmic microwave background radiation passed us by?
Mar 12, 2007
Episode 26: The Biggest Structures in the Universe
This week we continue the story of galaxy formation, learning how groups of galaxies come together to form the biggest structures around - galaxy superclusters. And when you look at the Universe at this scale, environment is everything.
Mar 05, 2007
Episode 25: How Galaxies Form
Our Milky Way is a complex and majestic barred spiral galaxy. But 13.7 billion years ago it began, like all galaxies, from the elementary particles formed in the Big Bang. How did our galaxy grow from nothing to the hundreds of billions of stars we see today?
Feb 26, 2007
Episode 24: Fermi Paradox
We live in a mind bogglingly big Universe filled with countless stars. We know intelligent life evolved here on Earth. It must be common across the Universe, right? But if there's life out there, how come we haven't been visited by aliens yet? Why haven't we even picked up signals from alien television stations? Where's all the life?
Feb 19, 2007
Episode 23: The Drake Equation
If you're wondering how many extraterrestrials there are in our galaxy, you just have to use a simple equation developed by astronomer Frank Drake in 1961. Just find out how many stars there are, how many support life, how many advanced societies form, and a few other details and we'll be set.
Feb 12, 2007
Episode 22: Variable Stars
Our Sun has been around for billions of years, and will last for billions more. We're lucky, it's pretty stable and reg