Take a fact-based journey through the cosmos. Tune in to hear weekly discussions on astronomical topics ranging from planets to cosmology. Hosted by Fraser Cain (Universe Today) and Dr. Pamela L. Gay (SIUE), this show brings the questions of an avid astronomy lover direct to an astronomer. Together Fraser and Pamela explore what is known and being discovered about the universe around us. Astronomy Cast is supported through individual donations and the sponsorship of Swinburne Astronomy Online.
Ep. 569: Ethics of Commercial and Military Space, Part 1: Private Space Flight
Every year, more and more people are making their way to space. Some private citizens have already gotten their astronaut wings, paying for a trip to space out of their own pocket. What are the ethical implications of this as the costs of spaceflight come down?
5/11/2020 • 27 minutes, 27 seconds
Ep. 568: In Situ Resource Utilization
The key to surviving in space will be learning how to live off the land. Instead of carrying all your fuel, water and other resources from Earth, extract them locally from your destination. It's called In Situ Resource Utilization, and if we can figure it out, it'll change everything.
5/6/2020 • 31 minutes, 29 seconds
Ep. 567: When Satellites Need a House Call
567: When Satellites Need a House Call Astronomy Cast 567: When Satellites Need a House Call by Fraser Cain & Dr. Pamela Gay Space is really far away, so when you send a satellite out into the void, that's pretty much the last you're going to be able to work on it. And if anything goes wrong, too bad, you're out a satellite. But a new test has shown that it's possible to actually visit and fix a satellite in space. Maybe we don't have to throw them all away after all.
4/27/2020 • 32 minutes, 3 seconds
Ep. 565: When Worlds Collide
565: When Worlds Collide Astronomy Cast 565: When Worlds Collide by Fraser Cain & Dr. Pamela Gay So much of our Solar System has been shaped by enormous collisions early on in our history. Seriously, the nature of every planet in the Solar System has some evidence of massive impacts during some point in its history.
4/13/2020 • 30 minutes, 57 seconds
Ep. 561: Remembering Katherine Johnson
561: Remembering Katherine Johnson Astronomy Cast 561: Remembering Katherine Johnson by Fraser Cain & Dr. Pamela Gay We lost a bright star here on planet Earth last week. NASA mathematician Katherine Johnson passed away at the age of 101, after an incredible career of helping humans land on the Moon. If you saw the movie Hidden Figures, you'll know what I'm talking about.
3/6/2020 • 33 minutes, 26 seconds
CosmoQuest Hangoutathon Promo
Hi everyone, Producer Susie here. This weekend, December 21-23, 2019, we will be having our CosmoQuest Hangoutathon. For 40 straight hours, our team will be bringing you guests, science and fun live on our channel. We are raising money to pay for our team to continue to bring you science, and for us to continue our citizen science programs, like the extremely successful Bennu Mappers from this past year, where over 3500 of you wonderful volunteers mapped over 14 million rocks on the asteroid Bennu, looking for a safe place for the OSIRIS-REx mission to grab samples to return to earth. We want to keep doing projects like this - and we need your help to continue doing the science. Please join us at starting 9am EST / 6am PST / 1400UTC. If you can’t tune in live, you can catch the replays on Twitch, and we’ll be trying our best to archive all of the content on YouTube after this weekend. We’re accepting donations at As part of the Planetary Science Institute, we are a 501c3 non-profit, so all of your donations are tax deductible where the law allows. Please watch, share and donate if you can, so we can keep bringing the science to you! Thank you for listening!
12/20/2019 • 1 minute, 42 seconds
Ep. 545: Weird Issues: Are comets asteroids or are asteroids comets?
545: Weird Issues: Are comets asteroids or are asteroids comets? Astronomy Cast 545: Weird Issues: Are comets asteroids or are asteroids comets? by Fraser Cain & Dr. Pamela Gay Things used to be so simple. Comets were snowballs from the outer Solar System, and asteroids were rocks from the inner Solar System. But now everything's all shades of grey. Astronomers have found asteroids that behave like comets and comets that behave like asteroids.
11/5/2019 • 29 minutes, 53 seconds
Halley's Meteor Shower and Two spacecraft updates
Got clear skies? Go out tonight and catch the Orionids Meteor shower, a storm of falling stars generated by Halley's comet. Later this week, we'll see aurora like those that will one day be predicted by the ESA Solar Probe. We also have an update on the Mars 2020 rover.
10/21/2019 • 7 minutes
Ep. 541: Weird Issues: Expansion Rate of the Universe
541: Weird Issues: Expansion Rate of the Universe Astronomy Cast 541: Weird Issues: Expansion Rate of the Universe by Fraser Cain & Dr. Pamela Gay Just when the Universe was starting to make sense, the cosmos throws a curveball at us. Astronomers have been trying to accurately measure the expansion rate of the Universe as far back as Hubble. It's been tough to nail down, and now astronomers are starting to figure out why.
10/7/2019 • 29 minutes, 1 second
Libsyn Survey Request
Please help us keep bringing you content by going to and filling out the survey, so Libsyn can find us sponsors for Astronomy Cast!
8/10/2019 • 54 seconds
Bonus Episode: Dust with Dr. Paul Sutter
Bonus: Dust with Dr. Paul Sutter Astronomy Cast Bonus: Dust with Dr. Paul Sutter by Fraser Cain & Dr. Pamela Gay Recorded during the Astrotour to Costa Rica, Fraser talks to Dr. Paul Matt Sutter about the nature of dust and BICEP 2's claim of discovering primordial gravitational waves.
3/17/2019 • 21 minutes, 10 seconds
436 Bonus: Moon Cheeziness
436 Bonus: Moon Cheeziness Astronomy Cast 436 Bonus: Moon Cheeziness by Fraser Cain & Dr. Pamela Gay
1/24/2017 • 12 minutes, 38 seconds
405: Method Not Found
AstronomyCast 405: Method Not Found
by Fraser Cain & Dr. Pamela Gay
3/7/2016 • 0
Weekly Space Hangout - May 3rd, 2013
5/4/2013 • 1 hour, 4 minutes, 35 seconds
Weekly Space Hangout Feb 15, 2013
2/16/2013 • 50 minutes, 43 seconds
Weekly Space Hangout Feb 8, 2013
2/8/2013 • 44 minutes, 42 seconds
Weekly Space Hangout Feb 1, 2013
2/4/2013 • 33 minutes, 14 seconds
Weekly Space Hangout - Jan 25 2013
1/25/2013 • 45 minutes, 54 seconds
Weekly Space Hangout - Jan 18, 2013
1/25/2013 • 49 minutes, 18 seconds
Weekly Space Hangout-Oct 25, 2012
10/27/2012 • 38 minutes, 21 seconds
Mobile App: Phases of the Moon
Universe Today needs your help. Support the site and enrich your life at the same time by buying our mobile app: Phases of the Moon, for both Android and iPhone. The app is only $.99 in the store or .
10/25/2012 • 1 minute, 22 seconds
Weekly Space Hangout - Oct 4, 2012
10/4/2012 • 35 minutes, 26 seconds
Weekly Space Hangout Sep 27, 2012
10/1/2012 • 47 minutes, 59 seconds
Weekly Space Hangout Sep 20, 2012
10/1/2012 • 49 minutes, 34 seconds
Weekly Space Hangout - Sep. 13, 2012
9/17/2012 • 51 minutes, 35 seconds
AstronomyCast: Live from DragonCon 2012
AstronomyCast: Live from DragonCon 2012, by Fraser Cain & Dr. Pamela Gay
9/11/2012 • 51 minutes, 42 seconds
Live coverage of the Curiosity Landing on August 5th, 2012
7/31/2012 • 1 minute, 32 seconds
Weekly Space Hangout - July 12, 2012
This week we talk about the new moon discovered orbiting Pluto (P5), New Horizons doing science in it's sleep, a southern polar vortex on Titan, and Pluto moon orbits, et cetera. We are joined by Robert Nemiroff, Jason Major, Alan Boyle, Michael Wall, Amy Shira Teitel and special guest Mark Showalter of SETI. Hosted by Fraser Cain.
7/12/2012 • 41 minutes, 53 seconds
Weekly Space Hangout - July 5, 2012
7/5/2012 • 40 minutes, 36 seconds
Weekly Space Hangout - June 28, 2012
6/28/2012 • 45 minutes, 46 seconds
Weekly Space Hangout - June 21, 2012
This week we talk about: Black Holes as particle detectors, New advances in Chinese space exploration, Asteroid research, History of women in space. We're joined by Amy Shira Teitel, Alan Boyle, Ian O'Neill, and Michael Wall. Hosted by Fraser Cain
6/22/2012 • 47 minutes, 36 seconds
Weekly Space Hangout - June 14, 2012
This week we talk about: Lakes on Titan, Mars Curiosity landing, Earth-type worlds more common, NuSTAR Mission launch. We are joined by Amy Shira Teitel, Emily Lakdawalla, and Nicole Gugliucci
6/22/2012 • 47 minutes, 59 seconds
Weekly Space Hangout - June 7, 2012
In this week's Weekly Space Hangout, we talk about the Transit of Venus, the transfer of the space shuttle Enterprise, the future of commercial space exploration, and the new movie Prometheus.
We're joined by Alan Boyle from http://cosmiclog.msnbc.msn.com/ and Amy Shira Teitel from http://www.amyshirateitel.com/
6/7/2012 • 50 minutes, 23 seconds
Weekly Space Hangout - May 31, 2012
In this episode of the Weekly Space Hangout, we're joined by special guest Robert Nemiroff from Astronomy Picture of the Day. We also talked about the return of the SpaceX Dragon capsule, a manned mission to Venus, nomadic planets and the announcement of the Square Kilometer Array.
Our team included: Amy Shira Tietel, Jason Major, Alan Boyle, Nicole Gugliucci and Robert Nemiroff
5/31/2012 • 53 minutes, 51 seconds
Weekly Space Hangout - May 17, 2012
Sorry for the lack of a Hangout last week, we had massive internet fail in Fraser's home city.
This week, we talk about: Building a real starship Enterprise, preparations for the annular solar eclipse, investigation into the Gaia theory, fuel for black holes, Hubble and the transit of Venus.
We're joined by Amy Shira Teitel, Jason Major, Nancy Atkinson, Nicole Gugliucci, Phil Plait.
5/23/2012 • 44 minutes, 36 seconds
Weekly Space Hangout - May 3, 2012
In this episode we talked about asteroid mining, SpaceX delays, Shuttle retirement, killer black holes, supermassive planets (aka brown dwarfs), Enceladus/Dione flybys, and missions to Jupiter.
5/4/2012 • 1 hour, 54 seconds
Weekly Space Hangout - Mar. 8, 2012
In this episode of the Weekly Space Hangout, we talk about two different asteroid close passes, the solar storms buffeting the Earth, a recent space exploration conference, and a team of amateur astronomers flashing the space station. We're also joined by Ryan Kobrick - Executive Director of Yuri's Night - to talk about the upcoming festivities.
3/8/2012 • 51 minutes, 49 seconds
Weekly Space Hangout - Mar. 1, 2012
Another week, another space roundup. This week we talk about the redefinition of the term "Earthlike", salty soil on Mars, how you can participate in SETI, asteroid dust from Hayabusa, and the dangers of a warp drive.
3/2/2012 • 39 minutes, 17 seconds
Weekly Space Hangout - Feb. 23, 2012
2/24/2012 • 57 minutes
Weekly Space Hangout - Feb. 16, 2012
2/16/2012 • 1 hour, 4 minutes, 40 seconds
Weekly Space Hangout - Feb. 9, 2012
2/13/2012 • 1 hour, 2 minutes, 59 seconds
Weekly Space Hangout - Feb. 2, 2012
2/13/2012 • 53 minutes, 11 seconds
Weekly Space Hangout - Jan. 26, 2012
Another edition of our weekly space hangout. This week we talked about a week of space remembrance, solar storms, Newt's plans for a 2020 lunar base, arsenic and old news, black holes and their galaxies and the death of Phobos-Grunt.
1/26/2012 • 1 hour, 1 minute, 28 seconds
Discovery of Earth-Sized Planets - Google+ Hangout
This is a Google+ Hangout we did to discuss the announcement of Earth-sized planets discovered by NASA's Kepler mission. Moderated by Fraser Cain from Universe Today/Astronomy Cast, with Nancy Atkinson from Universe Today, Dr. Phil Plait from Bad Astronomy, Emily Lakdawalla from the Planetary Society and Alan Boyle from MSNBC's Cosmic Log.
12/22/2011 • 55 minutes, 31 seconds
AstronomyCast: Live at Dragon*Con
AstronomyCast: Live at Dragon*Con, by Fraser Cain & Dr. Pamela Gay