Astronomy Cast

Streamed live 18 Oct 2026. Hosted by: Fraser Cain (@frasercain) and Dr. Pamela L. Gay (@CosmoQuest) Today we continue looking at space exploration technologies. This time we will examine thrusters, which can reorient a spacecraft and help it maneuver in space. Maximum flexibility but you need to bring along some propellant. Smarter Every Day's YouTube video: I Was SCARED To Say This To NASA... (But I said it anyway) https://www.youtube.com/watch?v=OoJsPvmFixU

Spinney things! Streamed live 18 Oct 2026. Hosted by: Fraser Cain (@frasercain) and Dr. Pamela L. Gay (@CosmoQuest) Our journey through space exploration technology continues! Today we look at the things that spin: gyros, reaction wheels, servos. Newton's laws are large and in charge today as spinning has a very useful benefit when you're in weightlessness! Today we are going to understand the nemesis of space exploration missions everywhere, get to the bottom of this, how these things works, why they fail, and maybe what's being done about it, or maybe not!

Ad-Free thanks to your support at patreon.astronomycast.com! Instead of sending up an entire space station for every mission, you can just send up a tiny can filled with astronauts. But that takes docking. And today we're gonna talk about what it takes to connect two spacecraft together. How to keep a cargo safe to get into orbit, and how to get in and out of your spacecraft without killing everyone! Hosted by: Fraser Cain (@frasercain) and Dr. Pamela L. Gay (@CosmoQuest) Streamed live on Oct 3, 2026. Mission Tech Part 3.

Hosted by: Fraser Cain (@frasercain) and Dr. Pamela L. Gay (@CosmoQuest) Streamed on October 3, 2026. Today our series continues with our deep dive into rockets, their engines & stages. We fall into the tyranny of the rocket equation and discover what it takes to escape Earth's gravity and head off into deep space. We removed all ads from the show. We need to get to 1,500 patrons to keep it this way. We need your support!

Help us keep Astronomy Cast ad-free: https://patreon.com/astronomycast We removed all ads from the show. We need to get to 1500 patrons to keep it this way. We need your support! Streamed live on Sep 21, 2026 Hosted by: Fraser Cain and Dr. Pamela L. Gay Today we begin a new series on rockets and spacecraft, dealing with each of their components. It's a big job, so it'll take us a bunch of episodes to get through. Today let's do an introduction about what we're gonna talk about in this series: rockets from tip to tail, soup to nuts.

Help us keep Astronomy Cast ad-free: https://patreon.com/astronomycast We removed all ads from the show. We need to get to 1500 patrons to keep it this way. We need your support! Streamed live on Sep 7, 2026. Hosted by: Fraser Cain (@frasercain) and Dr. Pamela L. Gay (@CosmoQuest) This show is supported through people like you on Patreon.com/AstronomyCast Today we do the sequel to our 2-part series. We jump to the end of the Universe, and all the major moments that will occur from now until the heat death of the Universe. The end of everything. - The fate & future of the Milky Way - Cosmic isolation - The cosmic microwave background - The end of star formation - The degenerate era - Proton decay and entropy - Black hole evaporation & entropy - Alternate endings, cosmic rip, new beginnings - Closing thoughts and updates

After 20 years, it's time to make some changes. With your patronage we can ditch the ads & turn up the science. Please join our Patreon community at patreon.astronomycast.com

Streamed live on Sep 7, 2026. Hosted by: Fraser Cain (@frasercain) and Dr. Pamela L. Gay (@CosmoQuest) This show is supported through people like you on Patreon.com/AstronomyCast To celebrate our 20th season, we thought we'd go back right to the beginning… of everything. Let's wind the clock back to the earliest moments of the Universe, where we'll measure time in fractions of a second. As the foundational laws of physics were laid down and we experience the repercussions to this day!

Astronomy Cast Ep. 799: Heavy Lift Rockets By Fraser Cain & Dr. Pamela Gay Streamed live June 22, 2026. The Saturn 5 was a monster, capable of sending humans and a lander to the Moon and bringing them back again. But the number of heavy lift rockets since then has gotten pretty sparse. Now, with tens if not hundreds of thousands of satellites in the works, giant new space telescopes and multi-ton lunar landers in development there are heavy lift solutions to match. So let's talk about them! From yesterday's Saturn V to today's Ariane VI, rockets capable of launching large telescopes or small space stations in a single go are modern marvels. They are also wildly dangerous, and not exactly compatible. Let's look at today's fleet of rockets and just what they're accomplishing. This show is supported through people like you on Patreon.com/AstronomyCast In this episode, we'd like to thank: Andrew Poelstra, Burry Gowen, David, David Rossetter, Ed, Eric Lee, Gerhard Schwarzer, Jason Kwong, Jeanette Wink, Joe McTee, Michael Purcell, Sergey Manouilov, Siggi Kemmler

Astronomy Cast Ep. 797: Summer in Space By Fraser Cain & Dr. Pamela Gay Streamed live June 10, 2026. We're about to take a much needed 2 month hiatus. But just because we're not here doesn't mean space stops existing and doing things. Today, let's give a preview of the big events due to happen in space this summer so you can prepare yourself and make sure you don't miss a thing! From meteors to moon landings and more, join Fraser and Pamela as the look at what you can enjoy this summer, after we go to hiatus in July. This show is supported through people like you on Patreon.com/AstronomyCast In this episode, we'd like to thank: Andrew Poelstra, Burry Gowen, David, David Rossetter, Ed, Eric Lee, Gerhard Schwarzer, Jason Kwong, Jeanette Wink, Joe McTee, Michael Purcell, Sergey Manouilov, Siggi Kemmler

Astronomy Cast Ep. 796: Oceans & Organics on Mars By Fraser Cain & Dr. Pamela Gay Streamed live on Jun 1, 2026. Mars is cold & dry today, but the evidence is growing that it used to be warmer & wetter. with seas & oceans that covered large parts of its surface. With the additional findings of the chemicals for life, the search for life on Mars is getting pretty interesting! New results from Perseverance and Curiosity describe a past Mars with complex chemistry and water. But did it have life? Background image credit: Kevin Gill This show is supported through people like you on Patreon.com/AstronomyCast In this episode, we'd like to thank: Andrew Poelstra, Burry Gowen, David, David Rossetter, Ed, Eric Lee, Gerhard Schwarzer, Jason Kwong, Jeanette Wink, Joe McTee, Michael Purcell, Sergey Manouilov, Siggi Kemmler

Astronomy Cast Ep. 795: Expanse Science By Fraser Cain & Dr. Pamela Gay Streamed live on May 10, 2026. This is the final episode of our series on sci-fi universes. And this week we will tackle "The Expanse". Now we've got fusion drives, Proto-matter, g-forces! Listen up, belta lawda! Let's look at the science of our own possible (with a side of aliens) future. This show is supported through people like you on Patreon.com/AstronomyCast In this episode, we'd like to thank: Andrew Poelstra, Burry Gowen, David, David Rossetter, Ed, Eric Lee, Gerhard Schwarzer, Jason Kwong, Jeanette Wink, Joe McTee, Michael Purcell, Sergey Manouilov, Siggi Kemmler

Astronomy Cast Ep. 794: Stargate Science By Fraser Cain & Dr. Pamela Gay Streamed live on May 10, 2026. We continue our ad-hoc miniseries through sci-fi franchises. This week we'll talk about Stargate, worm holes, mind parasites and self-replicating bots. There's a lot to talk about! This show is supported through people like you on Patreon.com/AstronomyCast In this episode, we'd like to thank: Andrew Poelstra, Burry Gowen, David, David Rossetter, Ed, Eric Lee, Gerhard Schwarzer, Jason Kwong, Jeanette Wink, Joe McTee, Michael Purcell, Sergey Manouilov, Siggi Kemmler

Astronomy Cast Ep. 793: Star Trek Science By Fraser Cain & Dr. Pamela Gay Streamed live May 4, 2026. Today we continue our mini-series; evaluating the science of various sci-fi franchises. We did Star Wars last week, this week tackle Star Trek. From transporters to warp drives, from phasers to photon torpedos. Let's tackle what Star Trek gets right and wrong about science. Let's look at the science of our galaxy, some day far in the future. This show is supported through people like you on Patreon.com/AstronomyCast In this episode, we'd like to thank: Andrew Poelstra, Burry Gowen, David, David Rossetter, Ed, Eric Lee, Gerhard Schwarzer, Jason Kwong, Jeanette Wink, Joe McTee, Michael Purcell, Sergey Manouilov, Siggi Kemmler

Astronomy Cast Ep. 792: Star Wars Science By Fraser Cain & Dr. Pamela Gay Streamed live April 29, 2026. May the fourth be with you! Isn't that what people say on the international holiday known as Star Wars Day? Today we're gonna talk about the science in everyone's favorite sci-fi fantasy stories. Which of it is real, and which is essentially magic? Let's find out! Let's look at the science of a galaxy long ago and far away. (Did you just hear the theme music in your head? We heard it start in our head!) This show is supported through people like you on Patreon.com/AstronomyCast In this episode, we'd like to thank: Andrew Poelstra, Burry Gowen, David, David Rossetter, Ed, Eric Lee, Gerhard Schwarzer, Jason Kwong, Jeanette Wink, Joe McTee, Michael Purcell, Sergey Manouilov, Siggi Kemmler

Astronomy Cast Ep. 781: Awakening Black Holes By Fraser Cain & Dr. Pamela Gay Streamed live on Feb 2, 2026. One long standing mystery in astronomy were the quasars. Incomprehensible energy blasting out of a point-like source, billions of light years away. We now know these are actively feeding supermassive black holes, which can turn off and on in a startlingly short period of time. Today: When black holes awaken! Our Universe is filled with sleeping monsters. And sometimes, whether we want it or not, they wake up hungry. In this episode, we take a look at the science behind how and why black holes of all sizes can go from nothing to the triggers of massive high-energy power release. This show is supported through people like you on Patreon.com/AstronomyCast In this episode, we'd like to thank: Burry Gowen, Eric Lee, Jeanette Wink, Michael Purcell, Andrew Poelstra, David, David Rossetter, Ed, Gerhard Schwarzer, Jason Kwong, Joe McTee, Sergey Manouilov, Siggi Kemmler, Sergio Sancevero Image credit: LOFAR/Pan-STARRS/S. Kumari et al.

Astronomy Cast Ep. 780: When Asteroids & Comets Attack! By Fraser Cain & Dr. Pamela Gay Streamed live on Jan 26, 2026. We live in a cosmic shooting gallery. It's not a matter of "if" but "when"! Dinosaurs, blah, blah, blah. You know the drill. But seriously, folks, it's raining rocks & ice out there! How seriously should we take it? What happens when a variety of different objects hit the Earth? Different kinds of objects affect Earth very differently when they impact. Let's discuss what makes an impactor more or less dangerous. This show is supported through people like you on Patreon.com/AstronomyCast In this episode, we'd like to thank: Burry Gowen, Eric Lee, Jeanette Wink, Michael Purcell, Andrew Poelstra, David, David Rossetter, Ed, Gerhard Schwarzer, Jason Kwong, Joe McTee, Sergey Manouilov, Siggi Kemmler, Sergio Sancevero

Astronomy Cast Ep. 779: Milankovitch Cycles By Fraser Cain & Dr. Pamela Gay Streamed live on Jan 12, 2026. Humans live short lives, and from our perspective the seasons are something that come and go with perfect regularity. But astronomers know the terrible truth! And that there are cycles that slowly shift over tens of thousands of years, shifting the cycles and the Earth's climate. Today we'll talk about the Milankovich Cycles! The Earth's orbit, tilt, and other physical attributes aren't quite as constant as you might think! Come learn how long-term changes do and don't affect our climate. This show is supported through people like you on Patreon.com/AstronomyCast In this episode, we'd like to thank: Burry Gowen, Eric Lee, Jeanette Wink, Michael Purcell, Andrew Poelstra, David, David Rossetter, Ed, Gerhard Schwarzer, Jason Kwong, Joe McTee, Sergey Manouilov, Siggi Kemmler, Sergio Sancevero

Astronomy Cast Ep. 778: Dyson Swarms By Fraser Cain & Dr. Pamela Gay Streamed live on Jan 5, 2026. Freeman Dyson asked a fascinating question. What would it look like if a civilization was using all the energy coming from their star? And what form would this take? This introduced the concept of a Dyson Sphere, or more realistically, a Dyson Swarm surrounding a star. But if you're skeptical about the concept, you're in good company. This show is supported through people like you on Patreon.com/AstronomyCast In this episode, we'd like to thank: Burry Gowen, Eric Lee, Jeanette Wink, Michael Purcell, Andrew Poelstra, David, David Rossetter, Ed, Gerhard Schwarzer, Jason Kwong, Joe McTee, Sergey Manouilov, Siggi Kemmler, Sergio Sancevero With special guest star Stella!

Astronomy Cast Ep. 777: The Eddington Limit By Fraser Cain & Dr. Pamela Gay Streamed live on Dec 29, 2025. How big can a star get? This is a calculation made by one of the original pioneers of modern astronomy, Sir Arthur Eddington. And it's named after him, the Eddington Limit. Now, astronomers are finding examples of giant black holes early in the Universe, calling into question some of Eddington's assumptions. Let's explore this fascinating concept! Why are stars sphere-ish? Why do blackholes not eat everything? Why do pulsating stars pulsate? It all comes down to work done by Eddington at the beginning of the last century, and today we're going to look back at Eddington's work and all its applications in modern Astronomy. This show is supported through people like you on Patreon.com/AstronomyCast In this episode, we'd like to thank: Andrew Poelstra, BogieNet, Brian Cagle, Burry Gowen, David, David Rossetter, Ed, Gerhard Schwarzer, Jason Kwong, Jeanette Wink, Michael Purcell, Sergey Manouilov, Siggi Kemmler, Sérgio Sancevero