There are asteroids and there are comets. But there’s an entirely separate class of objects called centaurs. But instead of half-human, half-horse, imagine an object that’s half comet, half asteroid but 100% interesting.
Our Hosts
Fraser Cain
Universe Today
Dr. Pamela Gay
CosmoQuest
Production by
- Richard Drumm, Audio Engineer
- Ally Pelphrey, Video Engineer
18 Seasons
700+ Episodes
2018 Winner Parsec Award
Ep. 613: Pluto’s Demotion: 15 Years Later
Astronomy Cast more than 600 episodes ago. Are there any updates? Does Pluto have a chance of regaining planethood again?
Ep. 612: Update: SETI, METI (and WETI)
Last week we talked about the various ways that astronomers could detect the presence of intelligent civilizations by observing technosignatures. This week we’ll give you an update on the state of searching for extraterrestrials. This field has gone from a collection of pariahs to a completely legitimate field of research. What’s changed?
Ep. 611: What is Required to Confirm Alien Life: Intelligence Edition
Last week we talked about what it’s going to take to confirm basic biological life across the Solar System and the Milky Way. This week, we’ll discuss what it’s going to take to detect intelligent life out there in space.
Recent Episodes
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. Episode 73: Questions Show #8...
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...
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...
Ep. 70: How To Win a Nobel Prize
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...
Student Questions: Farmersburg
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...
Ep. 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...
Ep. 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...
Ep. 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...
Ep. 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,...
Ep. 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...
Ep. 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...
Ep. 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...
Ep. 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...
Ep. 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...
Ep. 60: Questions Show #7
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...
Ep. 59: Saturn
Returning to our tour of 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...
Ep. 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...
Ep. 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...
Ep. 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...
Ep. 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...