Walkabout The Galaxy

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.

The Sun is showering us with far more gamma rays than anticipated according to new measurements from a Cerenkov radiation detector in Mexico. The way those gamma rays are produced is very cool. Also cool: data continue to suggest a significant problem with the so-called standard model of particle physics. Muons are misbehaving, and it may suggest a fifth, previously undescribed and unknown, force of nature. Check out all that cool stuff, silly sponsors and trivia, and space news on this episode of Walkabout the Galaxy.

We take a look at two extraordinary astronomical news items in this episode. A deep dive into an astronomical survey has discovered an Earth-sized rogue planet and a Neptune-sized rogue planet. Extrapolating from those discoveries, there may be trillions of Earth-sized rogue planets roaming the galaxy. That's more than the number of stars in the Milky Way! We also explore the question of early galaxies and a model that suggests the universe is older than the standard model. As a bonus, we have some wacky Top quark trivia, space news, and more.

The JWST has spotted water vapor in the hot inner region of a protoplanetary disk, the same region where rocky planets like are own are expected to form. This suggests water can be incorporated into terrestrial planets during formation, without relying on comet impacts. Much, much further away, a new interpretation of JWST results is consistent with dark stars. They are actually quite bright, but are powered by the annihilation of dark matter rather than by nuclear fusion. Catch up on these discoveries, planetary trivia, and much more with your friendly neighborhood astroquarks.

We think of aurora as an atmospheric phenomenon, but what happens when high energy particles from the Sun directly impact a planetary surface? Mercury reveals another cool planetary twist with auroral-like emission from its surface. Meanwhile, Jim and and Josh are gobsmacked by the old news of a big gravitational potential hump in the Indian ocean caused by upwelling of low-density magma far below. Catch up on all the cool space news with the astroquarks.  

Nature has provided us with exquisitely accurate clocks in the form of pulsars, those rapidly rotating neutron stars whose beams of radiation act like high-powered lighthouses across the galaxy. We discuss the amazing discovery of a deep, low, rumble of gravitational waves across the universe by analyzing the periods of 79 of those pulsar lighthouses. Closer to home, there's evidence for a major climate shift on Mars 400,000 years ago that lines up with changes in Mars's spin. Check it all out on this episode of WtG, with wave trivia and space news too.

Top quark has a field day in this episode with a model for fuzzy dark matter, new data that could shed light on dark energy, and a cool x-ray echo from the supermassive black hole at the heart of our galaxy. Closer to home, we take a look at how JWST is helping us determine if exoplanets have comfortable greenhouse effect atmospheres. Plus, we have a surprising spaceship trivia question and a space travel stumper. 

New analysis of radioisotopes of meteorites and the Earth suggest the Earth formed in only a few million years via a process called pebble accretion. This may mean the Earth’s water was incorporated early and gradually rather than through late impacts. Recent determinations of the historical length of the Earth’s day suggest it stalled out at 19 hours for a cool billion years, and we still have a ways to go to get to 25 hours when we can all sleep in. Find out about the Earth’s history, supermassive black hole mergers, and syzygy trivia.

There’s a bright supernova in a nearby galaxy, and a very distant supernova made brighter by the beauty of gravitational lensing. In another galaxy, a gargantuan black hole is revealed to be orbited by another supermassive black hole, resulting in a gamma ray flares as it rips through the main black hole’s accretion disk. Closer to home, we learn about new asteroid missions and a rapidly warming planet (hint: it’s ours). Plus: Harrison Ford and Leonard Nimoy trivia!