Astronomy Cast

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

Astronomy Cast Ep. 776: The Matter - Antimatter Dichotomy By Fraser Cain & Dr. Pamela Gay Streamed live on Dec 22, 2025. Shortly after the big bang there were almost exactly the same amounts of matter and antimatter in the Universe, but there was just enough of a difference that we live in a matter-dominated Universe. But it didn't have to be that way! Explaining this mystery has been one of the great mysteries in astronomy, and today we'll see if there's been any progress! Why is the Universe the way it is? Specifically, why is it made mostly of matter? This is the question we'll look at today! 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

Astronomy Cast Ep. 775: The Hydrogen 21-cm Line By Fraser Cain & Dr. Pamela Gay Streamed live on Dec 15, 2025. Atomic hydrogen is the raw material for stars, but there's a problem. It's cold & dark, but it can do a very rare trick, releasing a photon in a very specific wavelength, known as the 21 centimeter line. And thanks to this wavelength astronomers have mapped out star forming regions across the Milky Way, the Universe and into the Dark Ages! This forbidden transition of Hydrogen has led to the mapping of galaxy rotation, a cool classroom application of quantum mechanics, and weirdly no Nobel prize. In this episode, Fraser and Pamela take a look at this line's out-of-proportion awesomeness! 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

Astronomy Cast Ep. 774: How Does Bad Science Happen? By Fraser Cain & Dr. Pamela Gay Streamed live on Nov 8, 2025. Scientific expertise is under attack on all fronts with concerns coming from politicians and the public. While most of this is unwarranted and politically motivated, there can be germ of truth. Bad science does happen, but how? How is it that papers that very few believe still make it through peer review and to publication? Why do professors at prominent universities get quoted saying things that seem to be fiction? In this episode, we consider the case for letting potentially impossible things make it to publication. 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

Astronomy Cast Ep. 773: What Would You Do With $1 Billion For Astronomy? By Fraser Cain & Dr. Pamela Gay Streamed live on Nov 9, 2025. We are powerless fans of space exploration. But what if some fool gave us the authority and funding to make our space dreams a reality? Someone asked us what we'd do with a billion dollars. What missions? Which telescopes? But what if we had more? 100 Billion! A trillion! All the monies! You keep asking, and this week we answer you! Come hear what Fraser and Pamela would do if they were given complete control over $1billion that had to be used for 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

Astronomy Cast Ep. 772: 2025 Gift Guide By Fraser Cain & Dr. Pamela Gay Streamed live on Nov 9, 2025. It's time once again for our annual gift-giving guide. We've got recommendations for books, movies, TV shows, games, and of course astronomy gear to satisfy the space nerds in your family. The Christmas season is almost upon us, and with it comes excuses to inject science into the lives of those you love... or ask for them to give you that book, lens, or art print you already know you'll love. In this episode, Fraser and Pamela share the things they think would make good gifts for nerds like us. 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

Astronomy Cast Ep. 771: Comet Tails By Fraser Cain & Dr. Pamela Gay Streamed live on Nov 8, 2025. With the arrival of the comet 3I/Atlas (Asteroid Terrestrial-impact Last Alert System), the world is getting a crash course in comets, their behavior, and of course their tails. Today we're going to talk about comets and their tails, why they exist, how they grow, why they can be different colors and how they can be sometimes point AT the Sun. Comets are one of the most animated and ephemeral targets for astronomy. From night to night they can change in shape and color, and every nuance tells us something. In this episode, we decode blue tails, green cores, forward-facing plumes, and other weird and awesome details observed with these icy visitors. 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

Astronomy Cast Ep. 770: The Ethics of Mars Exploration By Fraser Cain & Dr. Pamela Gay Streamed live on Nov 3, 2025. Hosted by: Fraser Cain and Dr. Pamela L. Gay. It is arguable that humanity now has the technological ability to live on Mars. It would be done at enormous expense and sacrifice, and there are some tricky problems that we haven't solved yet. Although we could live on Mars, should we? There is a famous quote from Jurassic Park: "Your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should." This concept is played out across the sciences, and in planetary exploration, it requires us to ask, all because we can launch humans toward Mars, should we? 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

Astronomy Cast Ep. 769: Little Red Dots By Fraser Cain & Dr. Pamela Gay Streamed live on Oct 20, 2025. New instruments bring new mysteries, and when James Webb came on line it uncovered a collection of strange, compact, bright objects shifted deeply into the red end of the spectrum. These were dubbed “Little red dots” or LRDs. And the astronomical community continues to puzzle over what they are. When JWST first peered into the distant past, it discovered the early universe had a rash of little red dots. Their existence just 450 million years after the big bang meant either galaxies were forming way faster than anyone predicted, or something unimagined had been found. 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, David Truog, Ed, Gerhard Schwarzer, Jason Kwong, Jeanette Wink, Michael Purcell, Olger, Sergio Sancevero, Sergey Manouilov, Siggi Kemmler, Stephen Veit

Astronomy Cast Ep. 768: Comets' Unpredictability By Fraser Cain & Dr. Pamela Gay Streamed live on Oct 13, 2025. So it’s been decades since we’ve seen a bright comet in the sky. And actually there was a pair — Hale-Bopp and Hyakutake. And then, silence! And unmet promises by the Universe to give us a bright comet. Comets are unpredictable, and they arrive precisely when they intend to. Is it time again for a bright comet? If you asked us in January if 2025 was going to have any outstanding comets would fly through the Solar System, we would have (and we did) say "no." And we were wrong. Comets are fickle, unpredictable, and like to do exactly what we didn't predict. This show is supported through people like you on In this episode, we'd like to thank: Andrew Poelstra, BogieNet, Brian Cagle, Burry Gowen, David, David Rossetter, David Truog, Ed, Gerhard Schwarzer, Jason Kwong, Jeanette Wink, Michael Purcell, Olger, Sergio Sancevero, Sergey Manouilov, Siggi Kemmler, Stephen Veit

Astronomy Cast Ep. 767: Black Holes in Extreme Circumstances By Fraser Cain & Dr. Pamela Gay Hosted by: Fraser Cain and Dr. Pamela L. Gay Streamed live on Oct 6, 2025. You can only describe a black hole by its mass and its spin. And maybe it’s charge. But allow us to propose a new criteria: the personal experience. Some black holes have seen things… Experienced the laws of physics at their most extreme. And today we’ll tell their stories. The more of the sky we observe, the more bizarre situations we find black holes in. Let's explore! 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, David Truog, Ed, Gerhard Schwarzer, Jason Kwong, Jeanette Wink, Michael Purcell, Olger, Sergio Sancevero, Sergey Manouilov, Siggi Kemmler, Stephen Veit

Astronomy Cast Ep. 766: How Spacecraft End By Fraser Cain & Dr. Pamela Gay End-of-Life Planning for Your Spacecraft! Streamed live October 1, 2025. Your spacecraft has reached the end of its mission. You’ve done everything you can to keep it operational, but now it’s time to say goodbye. How do space agencies deal with spacecraft to shut them down gracefully, protect future missions and life on other worlds. So, the time has come to see your mission across the Rainbow Bridge. How exactly do you say goodbye? Let's discuss.

Astronomy Cast Ep. 765: Rockets vs The Environment By Fraser Cain & Dr. Pamela Gay Streamed live on Sep 22, 2025. We don’t launch a lot of rockets every year, so their impact on the environment is minimal compared to other forms of transportation. But that number is steadily increasing with rates that we’ll have to take seriously. What’s the current and future impact of rockets on the environment Rocket facilities are often surrounded by wildlife preserves and they always fly through our atmosphere. Let's take a look at how launches do and don't impact the environment around them from the surface of Earth, to the farthest orbits (and landings).

Astronomy Cast Ep. 764: Cleared For Launch! By Fraser Cain & Dr. Pamela Gay Streamed live September 17, 2025. This week, we look at the process behind rockets getting licensed to launch, and everyone around the pad getting notified to stay away as T-0 approaches. (Can you say "errant boat"?) We have a saying around here: “One does not simply book a return trip from a rocket launch.” That’s because they are an intensely complex chain of events that need to go right before it’s wise to let that rocket leave the launchpad.

Astronomy Cast Ep. 763: Interstellar Comets By Fraser Cain & Dr. Pamela Gay Streamed live Sep 8, 2025. Welcome to the first episode of our 19th season! This week we look at objects coming from other solar systems that come passing on by our Sun. During the summer hiatus the 3rd interstellar object was discovered: Comet 3I/ATLAS! So now we have 3 different interstellar interlopers to compare & contrast. What are we starting to learn about other star systems from this small sample size and how will our detection get even better? [Editor’s note: HiRISE’s telescope is 1/2 meter.]

Astronomy Cast Ep. 762: Science in Crisis - NASA’s New Budget By Fraser Cain & Dr. Pamela Gay Streamed live on Jun 30, 2025. Hosted by: Fraser Cain and Dr. Pamela L. Gay Normally we try to end the season on a high note. But there’s unfolding news that we just HAVE to cover before we leave you for the summer. NASA’s new budget is here, and it’s 25% smaller. We’ll cover what the changes are and try to understand the implications. It's a bad decade to be a researcher. We're going to look at why, and what US cuts will mean for the world. SUPPORTED BY YOU This Episode is made possible thanks to our Patrons on Patreon. Join at the Galaxy Group level or higher to be listed in our YouTube videos. Thanks to: BogieNet, Stephen Vei, Jeanette Wink, Siggi Kemmler, Andrew Poelstra, Brian Cagle, David Truog, Ed, David, Gerhard Schwarzer, Sergio Sancevero, Sergey Manouilov, Burry Gowen, David Rossetter, Michael Purcell, Jason Kwong

Astronomy Cast Ep. 761: It's Here! The Vera Rubin Observatory By Fraser Cain & Dr. Pamela Gay Streamed live June 25, 2025. The time has come. The mighty Vera Rubin Observatory has finally come on line and delivered its “first light” images. And by Pamela’s rules that means we get to talk about it! So let’s do that! After decades of waiting, we have images from Vera Rubin Observatory! SUPPORTED BY YOU This Episode is made possible thanks to our Patrons on Patreon. Join at the Galaxy Group level or higher to be listed in our YouTube videos. Thanks to: BogieNet, Stephen Vei, Jeanette Wink, Siggi Kemmler, Andrew Poelstra, Brian Cagle, David Truog, Ed, David, Gerhard Schwarzer, Sergio Sancevero, Sergey Manouilov, Burry Gowen, David Rossetter, Michael Purcell, Jason Kwong

Astronomy Cast Ep. 760: What to Look For This Summer By Fraser Cain & Dr. Pamela Gay Streamed live on Jun 16, 2025. It’s almost time for our annual summer hiatus, but before we go, we wanted to direct you towards all the fun and space stuff we’ll be enjoying this summer. We’ve got meteor showers, planets, rocket launches, TV shows, movies! Here’s what’s good. In a couple of weeks, we'll go on hiatus, but we want to make sure you are ready for stuff we can anticipate happening. SUPPORTED BY YOU This Episode is made possible thanks to our Patrons on Patreon. Join at the Galaxy Group level or higher to be listed in our YouTube videos. Thanks to: BogieNet, Stephen Vei, Jeanette Wink, Siggi Kemmler, Andrew Poelstra, Brian Cagle, David Truog, Ed, David, Gerhard Schwarzer, Sergio Sancevero, Sergey Manouilov, Burry Gowen, David Rossetter, Michael Purcell, Jason Kwong