Astronomy Cast

Episodes

Ep. 506: It’s not Aliens, Unless it’s Aliens

Nov 15, 2018 |

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.

Ep. 505: Seismology

Nov 8, 2018 |

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.

Ep. 504: Radar, Lidar, and Sonar

Nov 5, 2018 |

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.

Ep. 503: Gravity Mapping

Oct 24, 2018 | ,

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.

Ep. 502: No Touching: Determining Composition of Worlds Remotely

Oct 12, 2018 |

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.

Ep. 501: Water Worlds Revisited

Oct 5, 2018 |

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?

Ep. 500: Live Celebration!

Sep 12, 2018 | , ,

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.

Ep. 499: What is the proposed Hubble-Lemaitre Law?

Sep 10, 2018 | , ,

We started out Astronomy Cast with the controversial 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.