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Walkabout the Galaxy

Walkabout the Galaxy

364 episodes — Page 1 of 8

Little Plutino Has An Atmosphere and Making Sense of Saturn

May 13, 202647 min

Superkilonova and Artemis II Recap

Apr 28, 202645 min

Ep 422A Whisper of a Hint of Primordial Black Holes plus Earth BLOBs

Gravitational Wave observatory LIGO has seen a signature that looks like the merger of primordial (pre-stellar, big bang (not big band!) era) black holes. If confirmed with future observations, this would tell us a lot about the early universe and potentially shed light on dark matter. Finally! Plus, closer to home, the BLOBs in the Earth's mantle help us untangle the complicated past of our magnetic field.

Mar 18, 202640 min

Ep 419Supermassive Black Holes Supersoaking Other Galaxies

Supermassive black holes can be terrible neighbors. New research shows that their powerful jets of charged particles can shut down star formation in neighboring galaxies within the galaxy cluster, which is just plain rude. Closer to home, our own Down Quark Audrey Martin is part of a study shedding new light (with the James Webb Space Telescope) on the mysterious L type asteroids, that formed at very high temperatures early in our solar system's history.

Feb 25, 202638 min

Ep 418Snowball Earth was Cold and Scary and the Milky Way Magnetic Field is a Mess

The Earth spent some crazy amounts of time (tens of millions of years) completely frozen over. And not, in the grand scheme of things, all that long ago. New research shows the ocean was salty and super-cold. How did life survive? New techniques using radio observations reveal a complicated and twisty galactic magnetic field. Join us for an icy, winter olympics themed episode to find out all this and more.

Feb 18, 202646 min

Ep 417Planetary Nebulae and Active Asteroids Get a Closer Look

There's always been a fuzzy line between asteroids and comets, and new observations of asteroids in the vicinity of Jupiter provide a hint to the origin of the mysterious active asteroids that look like asteroids but act like comets. Elsewhere in the galaxy, the famous ring nebula gets a new spectral image that shows the presence of band of iron. Could it be the remnants of a planet like Earth or Mercury that was vaporized when the nebular formed? Tune in for our take on this, space news, trivia and much more.

Feb 5, 202641 min

Ep 416A Dark Universe Unveiled

Scientists head to the volcanic fields of Iceland to test instruments for the VERITAS mission to Venus, Artemis II is ready for its historic flight to the Moon, and the Dark Energy Survey reveals the distribution of dark matter on an astounding scale. For mind-blowing astro-stuff, space news, and trivia, join the astroquarks on Walkabout the Galaxy.

Jan 29, 202644 min

Ep 415Crazy Spinners in the Asteroid Belt and S8 Tension

The amazing discoveries from the Vera C. Rubin Observatory have already started, and the astroquarks take a look at some close to home. Asteroids bigger than a city block spinning in fewer than 5 minutes are just the beginning, and will change our understanding of the collisional evolution of the asteroid belt. The astroquarks muse on the biggest questions in astronomy today, and one of those, the so-called "S8 Tension" has a possible solution with the help of dark matter and neutrinos. Join us for all that, space news, trivia, and more.

Jan 14, 202646 min

Ep 414Cosmic Rays from Everywhere and Stringy Ancient Galaxies

The Parker Solar Probe flies through the Sun's corona, MAVEN has gone silent, and new data shed light on the origins of cosmic rays. JWST's observations of ancient galaxies reveal odd shapes that may be connected to dark matter. Join us for a year-end look at the latest discoveries and space news and much more.

Dec 17, 202542 min

Ep 413Interstellar Star Scars and Poop on Mars

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 hot stellar neighbors. If you wish you had more hot stellar neighbors, you should definitely check out this episode of Walkabout the Galaxy.

Dec 10, 202538 min

Ep 412Gravothermalizing and Baby Black Holes

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 friendly neighborhood astroquarks.

Dec 4, 202546 min

Ep 411An Ancient Moon of Mars?

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 that once filled the crater. Problem is, the age of the rocks and the magnitude of the tides would require a different moon than the ones currently there. Cool! Join us to hear about that, interstellar comet 3I/Atlas, and much more.

Nov 26, 202543 min

Ep 410Why Is There A Universe At All?

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 Collider provide a hint at explaining why there is matter in the universe and it was not all eliminated in a dramatic annihilation of matter-antimatter collisions. So, that's a relief! And we have space news, meta-trivia, solar system news and more. Join us, won't you?

Nov 20, 202536 min

Ep 409The Amazing and Crazy Story of Gemini and Jumbo Black Holes

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 were explored on the way to the Moon. Plus, top quark gives us a look at a new class of black holes that we've decided are "Jumbo Black Holes". All that plus twin trivia, a hot take, and more.

Nov 5, 202544 min

Ep 408Rings Around a Comet, Betelbuddy, and Odd Jupiter Moons

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 moons of Jupiter, and the puzzling stellar companion to Betelgeuse. Plus, top quark Jim Cooney stumps us with trivia.

Oct 29, 202549 min

Ep 407Adaptive LIGO and a New Look at an Old Crater

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 universe. And right here in our backyard, a suspicious sub-surface crater-like feature gets a new look that appears to confirm its extraterrestrial origin. Join us for space news, trivia, and more.

Oct 1, 202539 min

Ep 406Einstein Cross Reveals Dark Matter and a Life-y Mars Rock

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 gravitational lensing has enabled astronomers to map the distribution of dark matter in a small cluster of galaxies, providing a new tool to understand the distribution of this mysterious stuff. Join us for these stories, space news, space trivia, and a fake sponsor!

Sep 24, 202542 min

Ep 405Exo-Pluto Debris in Our Solar System and Axions Galore

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 axions in the great dark matter chase and a new way that JWST may help us answer it. Join us for all that, exoplanets, science fiction trivia and more.

Sep 10, 202546 min

Ep 404Europa 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.

Sep 3, 202537 min

Ep 403Trappist-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.

Aug 20, 202541 min

Ep 402Weird 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.

Aug 6, 202545 min

Ep 401Forbidden 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.

Jul 30, 202546 min

Ep 400Interstellar 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.

Jul 16, 202548 min

Ep 399Vera 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.

Jul 2, 202548 min

Ep 398Supernova 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!

Jun 18, 202540 min

Ep 397Cool 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.

Jun 4, 202540 min

Ep 396The 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.

May 21, 202547 min

Ep 395A 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.

May 14, 202541 min

Ep 394Vesta 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.

May 7, 202549 min

Ep 393Ultralight 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.

Apr 30, 202540 min

Ep 392Hot 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.

Apr 23, 202542 min

Ep 391Weird 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.

Apr 9, 202543 min

Ep 390Supernovas 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?

Apr 2, 202549 min

Ep 389Life 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.

Mar 26, 202543 min

Ep 388Are 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.

Mar 19, 202551 min

Ep 387Oort 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.

Mar 5, 202541 min

Ep 386Did 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.

Feb 26, 202536 min

Ep 385Hubble 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.

Feb 12, 202542 min

Ep 384Exocomets, 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.

Jan 29, 202544 min

Ep 383Little 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.

Jan 22, 202544 min

Ep 382Kiss 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.

Jan 15, 202546 min

Ep 381Quasi 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.

Jan 8, 202545 min

Ep 380Mysterious 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.

Dec 18, 202439 min

Ep 379Making 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.

Dec 11, 202437 min

Ep 378Neutrino 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.

Nov 27, 202443 min

Ep 377Not 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.

Nov 20, 202441 min

Ep 376Is 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.

Nov 6, 202442 min

Ep 375Trojan 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.

Oct 30, 202428 min

Ep 374Basin Instinct - Cosmological Structure and Edible Asteroids

We get a tour of our place in the grand cosmological scheme of things with new mapping of the local Basin of Attraction. Spoiler: also Jim's new stage name. And we explore the final frontier of In Situ Resource Utilization with studies of how to get edible nutrients from the raw materials in asteroids. It's a little bit gross. Plus space news, trivia, and more. Join us to learn about all this (and all of our new stage names).

Oct 23, 202445 min

Ep 373OG Top Goes to Europa

Original Top Quark Dr. Tracy Becker returns to her old stomping grounds to hang with the Walkabout crew and send Europa Clipper on its way to Jupiter. Join us for a preview of this mission's ambitious goals and the exciting journey it took to the launch pad. Also, new research suggests the Earth may escape a fiery death when the Sun becomes a red giant. We have, of course, space news, space history trivia, and much more.

Oct 9, 202450 min