Astronomy Cast

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 you ar...

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-funde...

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 throughout...

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 electronics seem ...

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). Let's...

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 know...

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-world mi...

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 Mars. I...

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 of th...

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. Supern...

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 its history and getting different results. Errors have mostly been ruled out, which leaves the potential for new physics. Has the strength of dark energy been changing over time? We thought Dark En...

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 and again. It’s time for an update on fast radio bursts, a phenomenon we’ve only known about for a few decades. In this time astronomers have learned a tremendous amount them. They’re not solved,...

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 gonna talk about rogue planets. Sometimes planets just go rogue. Let's learn about planets living free from stars. 

Show Notes:

Earth's Dust Storms

M...

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 how do they work differently on the worlds in the solar system. But what about the exoplanets?

The bane of solar panels, humans, and robots, dust storms have a way of picking up steam (or at least d...

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 discover these dangerous asteroids, measure their future impact risk and track the changes over time? When should we panic? New asteroids are found every day, and every day we learn that those asteroid...

Astronomy Cast Ep. 744: Lunar Time

By Fraser Cain & Dr. Pamela Gay

Streamed live on Feb 10, 2025.

What time is it? OK, fine, what time is it on the Moon? The Moon orbits the Earth, so it doesn’t fall into a specific time zone. Also, there’s lower gravity on the surface of the Moon, which changes the rate that clocks tick. Well… It’s time to introduce Lunar Time. 

When are you when you are ...

Astronomy Cast Ep. 743: What Else Can We Learn From Gravitational Waves?

By Fraser Cain & Dr. Pamela Gay

Streamed live on Feb 3, 2025.

Just a few years ago LIGO detected the first direct evidence of gravitational waves coming from colliding black holes. And there you have it. Boom! Black holes collide! But that wasn’t all we learned from gravitational waves, nor will we learn. Sure, the masses of merging black holes are nice to kno...