Walkabout The Galaxy

Water molecules have been observed on the surface of an asteroid for the first time, and new studies help explain some of the odd behavior of planetary ring systems, including why they even exist around small objects in the outer solar system. Join us for a clear and fun explanation, the latest from Mars, upcoming missions, space trivia and more.

In this special episode recorded live at MegaCon Orlando 2024, we are joined by NPR space reporter Brendan Byrne to take a close look at where we are in the mission to get people to the red planet. We take a look at the next steps in the Artemis program, and the history and future of robotic exploration of Mars. Find out when we will walk on Mars, where the best places to walk are, and we answer a listener question on the three body problem.

There's another claim for a violation of the cosmological principle - that all parts of the universe are basically the same on large scales - but Top quark Jim Cooney explains all is not lost for the standard model of the universe, and more observations are needed. The JWST is providing amazing observations near and far, and has now separately measured the composition of two orbiting trans-Neptunian objects (TNOs), confirming that they are made of the same stuff. We explain the implications of this together with the latest space news, a time loop stumper, and walkabout trivia.

Strange disappearing islands in the hydrocarbon lakes of Saturn's giant moon Titan may be fluffy icebergs of hydrocarbon snow. If you're on Titan, definitely don't eat the snow, yellow or not. As the Lucy mission heads towards the Trojan asteroids, questions remain about how this strange population of objects formed. We catch up with all the space news, a time travel stumper, and lunar exploration trivia.

What role has Jupiter played in the existence of our warm and cosy home planet? Has it been bravely using its gravity to keep the inner solar system calm, or did we luck out and escape getting hurtled out of the solar system or dashed to bits in a giant collision? We’ll discuss new research that explores exoplanetary systems with multiple large planets and whether habitable planets can co-exist with them. And within our own planet we learn about iron snow at the core mantle boundary and its effects on our magnetic field. Join us for all this cool stuff, plus space news and trivia.

New analysis of Cassini data suggests more complex hydrocarbons are part of Enceladus's global sub-surface ocean. We discuss the prospects for life on this tiny moon. The JWST continues to deliver scientific bonanzas, now providing direct observations of globular clusters in very distant galaxies, helping us understand these enigmatic and ancient structures. Join us to explore these mysteries and for space news and special down quark holiday-themed space trivia.

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). Speaking of super things, we also review the argument that we are located in a cosmological supervoid and whether than can explain some of the mysteries surround the Hubble constant. Join us for all that, space news, trivia and more.

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 meanwhile smash into the planets, and now a green glow from Mars' atmosphere has been observed by one of the many spacecraft exploring the red planet. We also discuss a surprising exoplanet discovery, moon trivia, space news and more.

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 when going to space. We’re busy littering already, but that’s just the tip of the asteroid. Join us for a discussion of some of the trickier issues of space exploration, space news, and gravitational wave trivia. The only place you can find that lineup is on Walkabout the Galaxy.

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 galaxy. We also take a closer look at the exciting results from the Lucy spacecraft's flyby of the asteroid Dinkinesh and its surprising moon. Join us for all this, space news, and top quark trivia.

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 universe starting with our observations of the cosmic microwave background are in disagreement (tension) with observations of the actual distribution of superclusters of galaxies. Are there errors that haven't been uncovered, or perhaps new physics? Join us for our thoughts on these and other news in space, and some literally mind-blowing trivia.

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 Venus. Our other planetary next-door neighbor, Mars, may have a deep molten magma ocean, revealed thanks to a fortuitous meteoroid impact on the planet whose shaking was recorded by Mars Insight. Join us for these insights, space news, and more.  

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 the otherwise invisible matter sprinkled in the intergalactic void. Somewhat closer to home, JWST is providing tantalizing glimpses of the composition of extrasolar planets, a technique that may one day discover alien life. Join us for these and other discoveries, space news, and podcast trivia.

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 comparing Fast Radio Burst statistics to earthquakes. This study suggests that these energetic bursts of radiation may be produced by quakes on neutron stars. Join us for these stories, space news, and space history trivia.

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 the role it may have played in the formation of Saturn’s rings. Plus, we have top quark trivia and a nerd news rant. Join us!

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 reproduced. Yet. A new detector in Australia will try to confirm the Italian result.

There's more tension in the standard model of the history of the universe. Giant superclusters of galaxies formed early than we thought they could. These collosal structures trace their origins to quantum fluctuations in the early universe. Find out what it all means, plus chthonian planets, asteroid encounters and more on Walkabout the Galaxy.

This episode is about hollows in space on very different scales and for very different reasons. Ho'oleilana is the largest observed structure in the universe, a bubble of sorts defined by great sheets of galactic superclusters whose size is a reflection of acoustic oscillations in the very early universe. Closer to home, we take a look at mysterious hollows on Mercury indicative of some sort of recent geologic activity. Join us to learn about these strange features, space news, radiation trivia and that unmistakable astroquark spark.

The astroquarks report from Dragoncon 2023 on the surprisingly diverse distribution of water in the solar system, where it came from, and the prospects for life on other worlds. We are joined by planetary geologist R. Scott Harris for this special episode with a live audience. This episode of Walkabout the Galaxy also features obscure sci-fi trivia, space news, and your hosts in silly costumes. 

When we think of all the wonderfully unique things about the Earth as a planet (liquid water on the surface, life, plate tectonics), the existence of lovely granite kitchen countertops doesn’t usually make the list. But it turns out granite is uncommon elsewhere in the solar system. But there’s a big hot blob of it underneath the lunar surface. We’ll explain that, the origin of diamonds on Earth, and take a closer look at the puzzling discrepancy of values of the Hubble constant thanks to JWST. Join us for all that and the first ever Charm Quark trivia.