Astronomy Cast

Science & Ideas

About

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 (Planetary Science Institute), 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 thru patreon.com/AstronomyCast.

Episodes

  • Ep. 794: Stargate Science

    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-r…

  • Ep. 793: Star Trek Science

    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…

  • Ep. 792: Star Wars Science

    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 abou…

  • Ep. 791: Chang'e Sample Return

    Astronomy Cast Ep. 791: Chang'e Sample Return By Fraser Cain & Dr. Pamela Gay Streamed live on Apr 20, 2026. Last week we talked about samples from other worlds delivered to Earth by meteorites. But sometimes you've gotta do the job yourse…

  • Ep. 790: Meteorites From Other Worlds

    Astronomy Cast Ep. 790: Meteorites From Other Worlds By Fraser Cain & Dr. Pamela Gay Streamed live April 17, 2026. Even though humanity has returned samples from a fraction of the worlds in the solar system, the cosmos has delivered many m…

  • Ep. 789: What Happens When a Planet's Star Dies

    Astronomy Cast Ep. 789: What Happens When a Planet's Star Dies By Fraser Cain & Dr. Pamela Gay Streamed live on Mar 30, 2026. A star like the Sun only lasts about 10 billion years and it becomes a red giant and finally a white dwarf. This…

  • Ep. 788: Life's Molecules Form in Space

    Astronomy Cast Ep. 788: Life's Molecules Form in Space By Fraser Cain & Dr. Pamela Gay Streamed live on Mar 23, 2026. The theory of evolution how life takes on its wildly different forms. But how did life get started in the first place? It…

  • Ep. 787: Evolved Stars (They're not dead yet!)

    Astronomy Cast Ep. 787: Evolved Stars (They're not dead yet!) By Fraser Cain & Dr. Pamela Gay Streamed live on Mar 16, 2026. Main sequence stars spend most of their time being… normal. Fusing hydrogen into helium in their cores. Producing…

  • Ep. 786: Wolf-Rayet Stars

    Astronomy Cast Ep. 786: Wolf-Rayet Stars By Fraser Cain & Dr. Pamela Gay Streamed live on Mar 9, 2026. You think the Sun is a terrifying ball of fire and fury? Wait until you learn about today's topic: Wolf-Rayet stars! These are massive,…

  • Ep. 785: Magnetars

    Astronomy Cast Ep. 785: Magnetars By Fraser Cain & Dr. Pamela Gay Streamed live March 6, 2026. Magnetars are a special type of neutron star with physics that defy comprehension. Magnetic fields so powerful they could strip you apart at an…

  • Ep. 784: Pulsar-Powered Science

    Astronomy Cast Ep. 784: Pulsar-Powered Science By Fraser Cain & Dr. Pamela Gay Streamed live on Feb 16, 2026. Pulsars are dead stars and fascinating in their own right, but astronomers can use their predictable rotation for exploring the c…

  • Ep. 783: Cataclysmic Variable Stars

    Astronomy Cast Ep. 783: Cataclysmic Variable Stars By Fraser Cain & Dr. Pamela Gay Streamed live on Feb 16, 2026. There are many types of variable stars. Today we're gonna talk about cataclysmic variable stars, which are the result of a wh…

  • Ep. 782: Luminous Fast Blue Optical Transients

    Astronomy Cast Ep. 782: Luminous Fast Blue Optical Transients By Fraser Cain & Dr. Pamela Gay Streamed live on Feb 13, 2026. Modern astronomy has found that the Universe can surprise us. Here's one which astronomers have called Luminous Fa…

  • Ep. 781: Awakening Black Holes

    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 l…

  • Ep. 780: When Asteroids & Comets Attack!

    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 dr…

  • Ep. 779: Milankovitch Cycles

    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 astronomer…

  • Ep. 778: Dyson Swarms

    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 w…

  • Ep. 777: The Eddington Limit

    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…

  • Ep. 776: The Matter - Antimatter Dichotomy

    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 th…

  • Ep. 775: The Hydrogen 21-cm Line

    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, releasi…

  • Ep. 774: How Does Bad Science Happen?

    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…

  • Ep. 773: What Would You Do With $1 Billion For Astronomy?

    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 m…

  • Ep. 772: 2025 Gift Guide

    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 astron…

  • Ep. 771: Comet Tails

    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…

  • Ep. 770: The Ethics of Mars Exploration

    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 Ma…

  • Ep. 769: Little Red Dots

    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 shif…

  • Ep. 768: Comets' Unpredictability

    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 t…

  • Ep. 767: Black Holes in Extreme Circumstances

    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…

  • Ep. 766: How Spacecraft End

    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…

  • Ep. 765: Rockets vs The Environment

    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 transpo…

  • Ep. 764: Cleared For Launch!

    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…

  • Ep. 763: Interstellar Comets

    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 ou…

  • Ep. 762: Science in Crisis - NASA's New Budget

    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 unfoldi…

  • Ep. 761: It's Here! The Vera Rubin Observatory

    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…

  • Ep. 760: What to Look For This Summer

    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 stuf…

  • Ep. 759: The Commercial Space Program

    Astronomy Cast Ep. 759: The Commercial Space Program By Fraser Cain & Dr. Pamela Gay Streamed live on Jun 9, 2025. Humanity has turned its focus back to the Moon, sending a fleet of spacecraft to the lunar surface. Some are run by the gove…

  • Ep. 758: Non-Roving Rovers

    Astronomy Cast Ep. 758: Non-Roving Rovers By Fraser Cain & Dr. Pamela Gay Streamed live on May 26, 2025. Some of our favorite robots are rovers currently roving around the surface of the Moon & Mars. But there's some pretty tricky terrain…

  • Ep. 757: CubeSats

    Astronomy Cast Ep. 757: CubeSats By Fraser Cain & Dr. Pamela Gay Streamed live on May 19, 2025. Computers are getting smaller, faster and more capable, which has enabled an entirely mew class of satellites: CubeSats. A mission small enough…

  • Ep. 756: SphereX

    Astronomy Cast Ep. 756: SphereX By Fraser Cain & Dr. Pamela Gay Streamed live on May 12, 2025. NASA's newly launched SphereX mission is up & operational and has completed its initial checkout and "first light". Everything looks good! And n…

  • Ep. 755: Intermediate Mass Black Holes

    Astronomy Cast Ep. 755: Intermediate Mass Black Holes By Fraser Cain & Dr. Pamela Gay Streamed live on May 5, 2025. Hosted by: Fraser Cain and Dr. Pamela L. Gay. There are stellar-mass and supermassive black holes. But very little evidence…

  • Ep. 754: K2-18b

    Astronomy Cast Ep. 754: K2-18b By Fraser Cain & Dr. Pamela Gay Streamed live on Apr 28, 2025. You've heard the news! Astronomers are reporting the discovery of biosignatures at K2-18b. Is this proof of life or should we all be more skeptic…

  • Ep. 753: Why is the Moon's South Pole So Interesting?

    Astronomy Cast Ep. 753: Why is the Moon's South Pole So Interesting? By Fraser Cain & Dr. Pamela Gay Streamed live on Apr 21, 2025. I'm sure you've heard that all eyes are on the Moon's southern pole. This is where various NASA and Chinese…

  • Ep. 752: Should We Go to the Moon or Mars Next?

    Astronomy Cast Ep. 752: Should We Go to the Moon or Mars Next? By Fraser Cain & Dr. Pamela Gay Streamed live on Apr 16, 2025. Hosted by: Fraser Cain and Dr. Pamela L. Gay There is an ongoing debate on where NASA should go next with humans:…

  • Ep. 751: Vacuum Energy

    Astronomy Cast Ep. 751: Vacuum Energy By Fraser Cain & Dr. Pamela Gay Streamed live on Apr 7, 2025. Hosted by: Fraser Cain and Dr. Pamela L. Gay. Even empty space isn't empty. It's filled with the quantum fluctuations of spacetime itself.…

  • Ep. 750: Supernova Early Warning System

    Astronomy Cast Ep. 750: Supernova Early Warning System By Fraser Cain & Dr. Pamela Gay Streamed live on Mar 31, 2025. Hosted by: Fraser Cain and Dr. Pamela L. Gay When enormous stars detonate as supernovae they release a burst of neutrinos…

  • Ep. 749: Dark Energy Changing Over Time

    Astronomy Cast Ep. 749: Dark Energy Changing Over Time By Fraser Cain & Dr. Pamela Gay Streamed live on Mar 24, 2025. The Hubble Tension is a vexing problem, with astronomers measuring the expansion of the Universe at different points in i…

  • Ep. 748: Fast Radio Bursts

    Astronomy Cast Ep. 748: Fast Radio Bursts By Fraser Cain & Dr. Pamela Gay Streamed live on Mar 17, 2025. For the briefest of moments, some dead stars can flash brighter than their entire galaxy (in Radio light) and then live to do it again…

  • Ep. 747: Rogue Planets

    Streamed live on Mar 10, 2025. Hosted by: Fraser Cain and Dr. Pamela L. Gay Most planets orbit stars. That's the rule, right? Well, maybe not. In fact the vast majority of planets could be floating freely through the Milky Way. Today we're…

  • Ep. 746: Dust Storms

    Astronomy Cast Ep. 746: Dust Storms By Fraser Cain & Dr. Pamela Gay Streamed live Feb 24, 2025. We have dust storms on Earth and of course the famous dust storms on Mars. There are even dust storms on Titan. What causes these storms and ho…

  • Ep. 745: How We Know If Asteroids Will Attack

    Astronomy Cast Ep. 745: How We Know If Asteroids Will Attack By Fraser Cain & Dr. Pamela Gay Streamed live Feb 20, 2025. I'm sure you've heard the news, asteroid 2024 YR4 has a tiny chance of hitting Earth in 2032. How do astronomers disco…