Walkabout the Galaxy

An irreverent and informative tour of the latest, greatest, and most interesting discoveries in astronomy.

Europa Clipper Report from Mars and ATLAS 3I Update from DragonCon 2025 09/03/2025

Europa Clipper Report from Mars and ATLAS 3I Update from DragonCon 2025 That's no error, this is episode 404, recorded in front of a live audience at DragonCon 2025 with special guest Trina Ray, Deputy Science Manager for the Europa Clipper mission. We get an update from the cool RADAR test the spacecraft conducted at Mars, new information on the history and composition of Interstellar Comet ATLAS 3/I and a super-duper-massive black hole. Join us for all this, 404 trivia, and more. /episode/index/show/walkaboutthegalaxy/id/38059235

Trappist-1, ESCAPADE, and Axions 08/20/2025

Trappist-1, ESCAPADE, and Axions There is so much going on in the universe it's hard to keep track. That's why we have not one but two top astroquarks on this episode to cover the latest discoveries and news from the solar system to the deepest recesses of space. A search for a habitable atmosphere comes up empty, while a mission to study the loss of Mars' atmosphere nears launch. And a clever new technique may be able to detect the hypothesized axion, a candidate particle for dark matter. Check it out, with space news, trivia, and more. /episode/index/show/walkaboutthegalaxy/id/37884840

Weird Black Hole Blazar and Water Ice Glaciers on Mars 08/06/2025

Weird Black Hole Blazar and Water Ice Glaciers on Mars There's more abundant and accessible water ice on Mars, ready for us to scoop it up, heat it up, and eat it up. And in the distant recesses of the universe there's a supermassive black hole with an interesting neighbor that causes a periodic splash of light. Learn all about it, plus trivia, fake sponsor, the Earth's puzzling spin, and much more. /episode/index/show/walkaboutthegalaxy/id/37705010

Forbidden Black Hole Merger and Chaos on Europa 07/30/2025

Forbidden Black Hole Merger and Chaos on Europa We discuss the largest black hole merger observed to date, between two black holes that are in the so-called forbidden mass range. They must have been created by some ancient merger of other black holes themselves. It's black holes everywhere you look these days. Closer to home, we take a look at Europa's weird Chaos terrain and new insights on how Mars lost its atmosphere. We also get a shout out from Audrey's dog. /episode/index/show/walkaboutthegalaxy/id/37593065

Interstellar Comet 3I/ATLAS is Out Of This World 07/16/2025

Interstellar Comet 3I/ATLAS is Out Of This World The astroquarks celebrate 400 episodes with a special sponsor, a special stumper, and a special interstellar comet making its way through our solar system from an origin near the galactic center perhaps as much as 7 billion years ago. /episode/index/show/walkaboutthegalaxy/id/37414685

Vera Rubin Observatory Sets Sights on the Universe 07/02/2025

Vera Rubin Observatory Sets Sights on the Universe The Vera C. Rubin Observatory has started making observations with the world's largest optical detector boasting over 3 billion pixels at the back of an enormous telescope in the high Andes. We take a look at some of the early discoveries and look ahead to what's in store for this enormous project as it plans to scan the sky hundreds of times at unprecedented detail over the course of the next decade. Plus: astronomy trivia, science hot takes, and more. /episode/index/show/walkaboutthegalaxy/id/37235805

Supernova Hazards and Cloudy With a Chance of Sand 06/18/2025

Supernova Hazards and Cloudy With a Chance of Sand We're all about the weather on this episode, with a new study showing that even relatively distant supernova may have affected the Earth's climate in the recent past. And the James Webb Space Telescope has observed exoplanet WASP-107b to have clouds of sand vapor. Plus, we have two hot takes and two Top astroquarks! /episode/index/show/walkaboutthegalaxy/id/37025800

Cool Planetary Cores and Lava Fountains Galore 06/04/2025

Cool Planetary Cores and Lava Fountains Galore Original top quark Tracy Becker is back to bring us up to speed Europa Clipper's flyby of Mars, and we learn about a new way for planetary cores to form without so much heat. Join us for all this, plus lava fountain trivia, space news, and much more. /episode/index/show/walkaboutthegalaxy/id/36839585

The End of the Universe As We Know It and We Feel Fine 05/21/2025

The End of the Universe As We Know It and We Feel Fine A major update to the predicted end of the universe has it coming much earlier than previously anticipated. However, we still have plenty of time to get our affairs in order, and the update has to do with spaghettification, and anything with spaghettification can't be all bad. We also talk about active asteroids, your ideal night sky, and cosmological trivia. /episode/index/show/walkaboutthegalaxy/id/36627145

A Slurping Black Hole and a Win for the Streaming Instability 05/14/2025

A Slurping Black Hole and a Win for the Streaming Instability We get lucky and catch a rogue supermassive black hole in the act of slurping up a star as it meanders through a distant galaxy. Closer to home, the detection of a second trinary, or triple, system in the Kuiper Belt beyond the orbit of Neptune bolsters the streaming instability theory of planet formation. We talk about all that and what it has to do with the Tour de France, as well as space news and trivia. /episode/index/show/walkaboutthegalaxy/id/36555070

Vesta Chip Off the Old Block and a Nearby Dark Molecular Cloud 05/07/2025

Vesta Chip Off the Old Block and a Nearby Dark Molecular Cloud The asteroid Vesta may be a fragment of a much larger protoplanet, and astronomers examine old data to discover a large molecular cloud lurking right in the solar system's backyard. Get all the details, plus habitable exoplanets get another look, space news, and trivial matters with your friendly neighborhood astroquarks. /episode/index/show/walkaboutthegalaxy/id/36467340

Ultralight Dark Matter and Peanut Asteroid Hot Take 04/30/2025

Ultralight Dark Matter and Peanut Asteroid Hot Take NASA's Lucy mission had a picture perfect encounter with the asteroid Donaldjohanson on its way to the first ever flybys of Trojan asteroids. Discoveries of ancient supermassive black holes challenge theories of their formation. If dark matter is composed of ultralight particles (lighter than a neutrino), that could resolve the mystery. Join us for these and other cosmic discoveries, space news, trivia, and more. /episode/index/show/walkaboutthegalaxy/id/36329290

Hot Takes on Water on Earth and Black Hole Singularities 04/23/2025

Hot Takes on Water on Earth and Black Hole Singularities The astroquarks discover hot takes and explore the nature of ice, the origin of Earth's water, and the trouble with the singularities at the hearts of black holes. Plus, we have a stumper, astronomical trivia, and much more. /episode/index/show/walkaboutthegalaxy/id/36234535

Weird Convection on Venus and a Wrinkle in the Lambda Cold Dark Matter Model 04/09/2025

Weird Convection on Venus and a Wrinkle in the Lambda Cold Dark Matter Model Venus's extra-thick crust may be extra chewy, allowing convection to occur and helping power volcanoes into the current era. New observations of the distant universe, meanwhile, show that dark energy may not have behaved as expected in the standard cosmological model. We'll break it all down for you together with space news and trivia with your friendly neighborhood astroquarks. /episode/index/show/walkaboutthegalaxy/id/36041860

Supernovas and Mass Extinctions 04/02/2025

Supernovas and Mass Extinctions A survey of nearby stars establishes the rate of supernovas in our general neighborhood. Evidence indicates we had nearby stellar explosions at the times of two mass extinctions. Those supernovas may have decimated the ozone layer and contributed to extinctions and climate changes. Plus, we recorded on April 1 and take a look at silly April 1 science papers, and we get tilted with our trivia and space news. Join us, won't you? /episode/index/show/walkaboutthegalaxy/id/35975860

Life on Hycean Worlds, Interstellar Debris, and Dark Matter Survey 03/26/2025

Life on Hycean Worlds, Interstellar Debris, and Dark Matter Survey If there are Hycean worlds and if they have a certain kind of microbial life and if there is enough of it, JWST might be able to see the chemical products of that in the planet's atmosphere. We take a look at that, debris from neighboring stars entering our solar system, and the first results from the Euclid space telescope. Join us for all this plus a hilarious double stumper and more. /episode/index/show/walkaboutthegalaxy/id/35870575

Are We Inside a Black Hole? 03/19/2025

Are We Inside a Black Hole? There are exciting new observations from recent lunar missions, a possible chunk of the Moon keeping us company, and an intriguing observation supporting the theory that the entire universe is inside a black hole! Get inside the event horizon with the astroquarks for all the space updates, trivia, and more. /episode/index/show/walkaboutthegalaxy/id/35768895

Oort Cloud Spiral, the Color of Mars, and a New Dwarf Galaxy 03/05/2025

Oort Cloud Spiral, the Color of Mars, and a New Dwarf Galaxy We take a look at the formation and structure of the Oort cloud of comets which is spherical at large distances but has a spiral structure in its inner regions. And, after all this time, there's a surprising twist on the nature of the iron mineral that gives Mars its reddish hue. Also hiding in plain sight is a dwarf galaxy in the neighborhood of the Andromeda galaxy, our largest companion galaxy. Join us for a discussion of these discoveries, trivia, space news and more. /episode/index/show/walkaboutthegalaxy/id/35528390

Did You Quipu? 02/26/2025

Did You Quipu? Lunar exploration continues to accelerate, and there's a new longest "structure" in the universe. Quipu is a quasi-alignment of clusters of galaxies stretching over 1 billion light years. Structure is in cynical quotation marks because these objects are not bound or connected to each other in any way, but their arrangement is a natural consequence of the evolution of the universe. If we happen to be in a Quipu-like structure ourselves, that may help us get out of our Hubble tension problem. Join us for cosmological mind-benders like this, and updates on ocean worlds and other moons closer to home, as well as space news and trivia. /episode/index/show/walkaboutthegalaxy/id/35431710

Hubble Tension Won't Go Away But Some Exoplanets Do 02/12/2025

Hubble Tension Won't Go Away But Some Exoplanets Do The more measurements we make of the expansion of the universe, the more it seems as though Hubble Tension is not a problem with our data but a problem with our understanding of the expansion of the universe. We'll talk about that, and some cool new observations closer to home, including a disintegrating exoplanet that is giving us a unique peak into a planet's insides. Join us for all this and more, including space news and trivia. /episode/index/show/walkaboutthegalaxy/id/35245345

Exocomets, Io, and the Great Dimming of T Tauri 01/29/2025

Exocomets, Io, and the Great Dimming of T Tauri Juno reveals a surprise about the interior of Jupiter's volcanic moon Io, and the OG young variable star T Tauri is getting ready to fade from view thanks to its dusty neighbors to the south. Speaking of dust, that's what gets kicked up when comets collide, and a new survey examines the cometary belts around dozens of star systems, providing a detailed look at the outer reaches of exoplanetary systems. Join us for all this, sample return stumpers, and Top Quark trivia. /episode/index/show/walkaboutthegalaxy/id/35017685

Little Red Dots and Big Black Holes 01/22/2025

Little Red Dots and Big Black Holes The discoveries from the James Webb Space Telescope keep coming. After showing that galaxies formed far earlier than we thought, we now have a better understanding of what was going on in the early universe. Those little red dots spied by JWST are actually the glow of heated dust and gas from supermassive black holes, and not the glow from billions of stars as had been thought. Closer to home, did the Earth sport a ring for a few million years? Analysis of ancient craters suggests it may have. Tune in to get the full story, plus gravitational trivia, space news, and more. /episode/index/show/walkaboutthegalaxy/id/34943090

Kiss and Capture for Pluto and Charon and Dark Energy Remains Dark 01/15/2025

Kiss and Capture for Pluto and Charon and Dark Energy Remains Dark Pluto and its largest moon, Charon, orbit each other with gazes lovingly fixed on each other, held in place by a romantic tidal attraction. But Charon's large size has always been difficult to explain. New simulations show that their love affair may have started at the beginning with a "Kiss and Capture" collision, much gentler than the devasting impact that formed our own Moon. Hear all about that, Centaurs, space news, space trivia, and a new way to explain away Dark Energy with your friendly neighborhood astroquarks. /episode/index/show/walkaboutthegalaxy/id/34826625

Quasi Particles, Pluto's Moons, and Cosmic Rays 01/08/2025

Quasi Particles, Pluto's Moons, and Cosmic Rays We kick off 2025 with oddities from quasi particles, to cosmic rays, to the moons of Pluto. What has mass when it moves in one direction and doesn't when it moves in another direction? How do thunderstorms on Earth interact with cosmic rays? What is up with Pluto's moons? Join us as we tackle these questions as well as the stumper and special top quark trivia. It's all part of the package in an episode of Walkabout the Galaxy. /episode/index/show/walkaboutthegalaxy/id/34768130

Mysterious Dark Comets 12/18/2024

Mysterious Dark Comets We know about extinct comets and active asteroids, but now we've got something in between: dark comets, whose orbits indicate cometary activity, but we can't see it! We'll get the scoop on these interesting objects, a flare from a supermassive black hole, and a twist on the question of the age of Saturn's rings. Plus, we have our end-of-the-year rocket launch roundup, and a special astrophysical FLOD stumper for top quark Jim Cooney. /episode/index/show/walkaboutthegalaxy/id/34495540

Making Big Blobs is Hard 12/11/2024

Making Big Blobs is Hard Top quark Jim Cooney explains why making big blobs is hard and how new observations are helping us understand how the universe made big immensely big blobs more commonly known as giant elliptical galaxies. Nature loves to make a disk, and we love to tell you all about the cool things nature does, including a solid state greenhouse on ancient Mars that may have produced a huge buried supply of water to create giant rivers near its south pole. Join us for this and more mind-blowing stuff. It's all part of our Walkabout the Galaxy. /episode/index/show/walkaboutthegalaxy/id/34358820

Neutrino Fog and the Hunt for Dark Matter 11/27/2024

Neutrino Fog and the Hunt for Dark Matter It's a good news bad news story with the detection of the neutrino fog. This signal from solar neutrinos may confound our search for certain dark matter candidates, but at least we know our detectors are very, very sensitive! We also take a look at magnetic fields in the outer solar system, specifically why Uranus's magnetosphere was so weird when we visited in 1986, and what tiny grains from a near Earth asteroid may be telling us about the magnetic field four and a half billion years ago. Join us for all that, and of course space news and stupid trivia. /episode/index/show/walkaboutthegalaxy/id/34150880

Not All Supernovae Are Created Equal 11/20/2024

Not All Supernovae Are Created Equal If you're speaking English, not Latin, do you really have to say "supernovae" instead of "supernovas"? Also, they are, in some sense, created equally: explosion of a white dwarf, but the outcomes are not all equal. You are welcome for this grammatical tangent, and please enjoy our fun discussion about weird tesserae (more Latin!) on Venus and the whole standard candle story of type 1a supernovae gets a rewrite. On this episode of Walkabout the Galaxy, you can also enjoy solar energy/spacecraft trivia, space news, and general hilarity at no extra charge. /episode/index/show/walkaboutthegalaxy/id/34018752

Is There Another Belt of Comets? 11/06/2024

Is There Another Belt of Comets? New observations contradict earlier studies about the possibility of another belt of comets orbiting the Sun twice as far away as Pluto. We'll take a look at what's what in the outer solar system and also explore whether black holes may help explain the Hubble tension. We also play FLOD (Flyby, Land, Orbit, Destroy) and have some "how many planets" trivia. /episode/index/show/walkaboutthegalaxy/id/33757257

Trojan Asteroids Everywhere 10/30/2024

Trojan Asteroids Everywhere Join Strange and Down quarks for a close look at Trojan asteroids, the forgotten asteroids of the solar system. NASA's Lucy mission is en route to take our first close look at these denizens of the outer solar system and has an Earth gravity assist in December 2024. As you'll see in our trivia, the numbers of Trojans may surprise you. Jupiter is the king of the Trojans, but we'll take a closer look at the first comfirmed Trojan of Saturn. /episode/index/show/walkaboutthegalaxy/id/33679492

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