Astronomy Cast

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...

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 the...

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 co...

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 sur...

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 ...

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 ...

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....

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!

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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 yo...

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 government, but there's a whole new group of commercial landers bearing instruments to the lunar surface. Is this the future of lunar exploration? Space used to be a place occupied by government-f...

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 out there and engineers are scheming up clever ways to explore other worlds inspired by life that crawls, slithers, hops and flies. As we explore more surfaces and more complex surfaces th...

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 that you can hold it in your hands, and yet powerful enough to even travel to other planets and send messages home. 

Every year, our ele...

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 now it's starting its science operations. And that's good enough for Pamela! And THAT means we can talk about it. So let's do that! There's a new space telescope in town (or at least in LEO...

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 of anything in between. Where are all the intermediate-mass black holes that should be the building blocks of the biggest ones? Actually, the science has been accelerating rapidly and we now ...

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 skeptical? It's in the news and people are claiming aliens... but is it aliens? Let's see what the data actually says. 

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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 missions are targeting. What makes this region so special and what are the special challenges that explorers will face. From TV shows to real...

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: to the Moon or Mars. (Or maybe an asteroid or one of Mars' moons). We are on the verge of sending humans back to the Moon. At the same time others would prefer we focus our exploration on Mar...

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. Which can be measured with famous experiments like the Casimir Effect. There is a surprising amount of energy in space itself, which has led to some interesting theories about how the future o...

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 that can be the first sign of a coming explosion. Now, astronomers have built a network to watch for that flash of neutrinos, and help direct their telescopes for when the sky show begins. Su...