Supernovas and Mass Extinctions
Walkabout the Galaxy
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?
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Life on Hycean Worlds, Interstellar Debris, and Dark Matter Survey
Walkabout the Galaxy
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.
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Are We Inside a Black Hole?
Walkabout the Galaxy
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.
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Oort Cloud Spiral, the Color of Mars, and a New Dwarf Galaxy
Walkabout the 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.
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Did You Quipu?
Walkabout the Galaxy
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...
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Hubble Tension Won't Go Away But Some Exoplanets Do
Walkabout the Galaxy
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.
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Exocomets, Io, and the Great Dimming of T Tauri
Walkabout the Galaxy
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.
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Little Red Dots and Big Black Holes
Walkabout the Galaxy
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.
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Kiss and Capture for Pluto and Charon and Dark Energy Remains Dark
Walkabout the Galaxy
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.
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Quasi Particles, Pluto's Moons, and Cosmic Rays
Walkabout the Galaxy
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.
info_outlineA clever test of dark matter and an alternative theory of gravity to explain the motions of stars around galaxies results in another check in the win column for dark matter. Simulations with the modified model of gravity failed to explain the motions in the inner regions of galaxies. Meanwhile the search for a hypothesized large object in the distant reaches of our solar system has so far come up empty suggesting that it may be larger and more distant than previously thought. Join us for all the intriguing and exciting space news in the universe!