Astronomy Cast Full Raw Feed

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.

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.

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.

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?

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. Astronomy Cast celebrated their 500th episode on Sept 15-16, 2018. We broadcasted from our celebration, in front of a live audience! And we debuted our new theme music by c...

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.

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.

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.

Another update show, this time on the various generations of stars, let's get into it.

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?

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?

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?

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?

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.

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.

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.

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?

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.

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.

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.

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.

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?

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.

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 maneuvers. Let's talk about what happens after the rocket is long gone, beyond our sight.

Pamela will be on to answer your space and astronomy questions live, as Fraser enjoys auroras in Iceland this week!