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
Pluto Cryovolcano and a Cosmological Supervoid [not-audio_url] [/not-audio_url]

Duration: 42:52
At Pluto's frigid temperatures, even what we breathe is frozen. This can give rise to unusual cryovolcanism, and new research suggests a super cryovolcano tens of kilometers across on the ninth planet (yes, we went there…
Mysterious Cosmic Ray and Martian Airglow [not-audio_url] [/not-audio_url]

Duration: 46:36
The second most energetic cosmic ray (really a particle) ever observed smashed into the Earth a couple of years ago, raising more questions about the origins of these incredibly energetic particles. Solar wind particles…
Ethical Dilemmas in Space Exploration [not-audio_url] [/not-audio_url]

Duration: 45:29
The astroquarks are joined by Dr. Erika Nesvold, astrophysicist and author of "Off Earth: Ethical Questions and Quandaries for Living in Outer Space" to explore some of the surprising problems people need to think about…
The Origin of Supermassive Black Holes [not-audio_url] [/not-audio_url]

Duration: 41:07
JWST data confirm early formation of supermassive black holes, less than 500 million years after the big bang. This early formation suggests these monsters start off very large and form with the initial formation of the…
Dinky and the S8 Tension [not-audio_url] [/not-audio_url]

Duration: 51:01
The Lucy spacecraft had its first asteroid encounter, revealing Dinkinesh to be a binary asteroid. In cosmology, a new simulation with a terrible acronym leaves the "S8 Tension" intact. Models of the expansion of the uni…
The Surprising Interiors of Mars and Venus [not-audio_url] [/not-audio_url]

Duration: 47:10
New research suggests that Venus, Earth's twin gone bad, may have started off with tectonic plate activity, like Earth. This will help us understand the evolution of Earth-like planets and why they become hothouses like…
Detecting ETs and Intergalactic Baryons [not-audio_url] [/not-audio_url]

Duration: 46:20
Fast Radio Bursts are back, this time providing a crucial measurement of the amount of normal matter in the universe. Top quark Jim Cooney explains how the interaction of light from very distant gamma ray bursts reveals…
Neutron Star Quakes and the Streaming Instability [not-audio_url] [/not-audio_url]

Duration: 49:25
Images of the distant Kuiper Belt Object Arrokoth add more weight to the pebble accretion model of planetesimal formation via the streaming instability. If that sounds strange, then you'll really love the story about com…
Pangaea Ultima, Antimatter Gravity, and the Evection Resonance [not-audio_url] [/not-audio_url]

Duration: 51:21
The next supercontinent could spell bad news for mammals. The equivalence principle passes another test, with antimatter atoms falling just like normal matter atoms, and Josh gets excited about the evection resonance and…
Short Take: Asteroid Sample and Dark Matter Hopes [not-audio_url] [/not-audio_url]

Duration: 19:22
Strange and Top discuss the return of the sample from the asteroid Bennu and an intriguing measurement from a dark matter detector in Italy in this, our first Short Take episode. Sadly, the measurement has not been repro…