Second Generation Black Hole Mergers and Solar System Chaos

Second Generation Black Hole Mergers and Solar System Chaos

Author: Joshua Colwell, Adrienne Dove, and James Cooney June 4, 2026 Duration: 46:34

Exquisitely detailed measurements of the ripples in spacetime from the mergers of black holes now show that some of these merging black holes were, themselves, created by an earlier black hole merging event. While this had been suspected to take place, we now have clear evidence of it. On a less dramatic scale but much closer to home, new simulations of the early solar system suggest the large population of moons of Uranus needed help from a now long lost fifth giant planet to survive. Join us for all this, space news, trivia, and a generally good time.


Ever wondered what it would be like to grab a coffee with a few planetary scientists who can’t help but find the humor in the cosmos? That’s the feeling you get with Walkabout the Galaxy. Hosted by Joshua Colwell, Adrienne Dove, and James Cooney, this isn’t a dry lecture from a distant lecture hall. Instead, it’s a lively, often funny conversation that feels like you’re right there with them, unpacking the universe’s latest headlines. Each episode digs into the newest and most fascinating discoveries in astronomy and space science, but the approach is grounded and genuinely curious. You’ll hear the hosts’ real excitement and occasional friendly debates as they translate complex ideas from recent papers or major missions into stories anyone can connect with. The tone is naturally irreverent, which makes the science stick, and their camaraderie turns each discussion into an engaging journey. Tuning into this podcast means getting a front-row seat to a casual yet deeply informative chat about everything from quirky asteroids to the profound mysteries of distant galaxies, all delivered with a warmth that reminds you why looking up at the stars is so compelling in the first place. It’s a perfect blend of solid science and natural comedy, making the vastness of space feel a little more like home.
Author: Language: English Episodes: 100

Walkabout the Galaxy
Podcast Episodes
Interstellar Star Scars and Poop on Mars [not-audio_url] [/not-audio_url]

Duration: 38:58
We explore the dining and drinking choices for astronauts, complex chemicals discovered in asteroid samples, and untangling the web of scars in the local interstellar cloud to reveal past encounters of the Sun with some…
Gravothermalizing and Baby Black Holes [not-audio_url] [/not-audio_url]

Duration: 46:48
There's a new funky proposal for small black holes in the early universe, and another potential dark matter candidate. Learn about cannibal stars and much more, together with double trivia and space news with your friend…
An Ancient Moon of Mars? [not-audio_url] [/not-audio_url]

Duration: 43:29
The story behind this investigation is almost more cool than the discovery itself. Microlayers of sediments in Mars' Gale Crater, observed by NASA's Curiosity rover, are indicative of tidal sloshing of water in the lake…
Why Is There A Universe At All? [not-audio_url] [/not-audio_url]

Duration: 36:02
Things would be a lot simpler and a lot less interesting if charge parity existed in the universe, but there would be no one to appreciate that simplicity because we would not exist! New results from the Large Hadron Col…
The Amazing and Crazy Story of Gemini and Jumbo Black Holes [not-audio_url] [/not-audio_url]

Duration: 44:46
The astroquarks are joined by Jeffrey Kluger, editor at large at Time Magazine and author of 13 books including Apollo 13 and the new book on the Gemini program. Tune in to hear about some of the outlandish ideas that we…
Rings Around a Comet, Betelbuddy, and Odd Jupiter Moons [not-audio_url] [/not-audio_url]

Duration: 49:48
These rings aren't around Uranus, they're somewhere even more odd. We discuss the mysterious and changing ring system around the Centaur object Chiron, new clues about the origin of the solar system from the irregular mo…
Adaptive LIGO and a New Look at an Old Crater [not-audio_url] [/not-audio_url]

Duration: 39:33
Adaptive optics techniques get applied to the mirrors in the LIGO gravitational wave observatory, promising a five-fold or greater improvement in sensitivity to gravitational waves from colliding black holes across the u…
Einstein Cross Reveals Dark Matter and a Life-y Mars Rock [not-audio_url] [/not-audio_url]

Duration: 42:00
We take a look the Cheyava Falls rock on Mars, or rather the Perseverance rover took a look at it, and we discuss what it saw which were some intriguing mineral formations that could have a biological origin. And gravita…
Exo-Pluto Debris in Our Solar System and Axions Galore [not-audio_url] [/not-audio_url]

Duration: 46:33
An interstellar interloper may have been a chip off the old block, where the old block was a Pluto-like planet around another star, and the chip is solid air (nitrogen that is)! And we revisit the potential role of axion…