Walkabout the Galaxy

What if the stuff that makes up most of the stuff in the universe is so lightweight that you could barely call it stuff? Ultralight dark matter is one possible way to explain the puzzle of the very early formation of supermassive black holes. We explore this and the intriguing origins of Ceres, and much more.

We like to think we understand ordinary matter: the stuff we're familiar with that makes up stars, planets, and donuts. Sure Dark Energy and Dark Matter are mysterious, but the rest we have a handle on. Or do we? The New Horizons mission adds to a growing puzzle about the Cosmic Optical Background, not to be confused with the Cosmic Microwave Background, which is a beast of an entirely different c...

Even the emptiness between galaxies is filled with enough energy over those vast expanses to generate shock waves and giant structures when clusters of galaxies collide. We explore this, the lives of galaxies, and some intriguing results about activity on the asteroid Ceres.

We learn how binary star systems may create a second family of planets, Saturn's aurora may be powered by the ringed planet's high speed winds, and how thinking of planetary intelligence may guide future searches for extraterrestrial life. 

A remarkably accurate test of general relativity confirms that not only does time run slower at your feet than at your head, but it runs slower at your eyes than your eyebrows. Plus, Psyche loses some of its metallic sheen, and we have spacewalk trivia and much more.

Sustained fusion reactions with a net production of energy may be getting closer, and a whole bunch of space junk is definitely getting closer. A long-standing mystery of Jupiter's aurorae has been resolved. Catch up on all the space news and hear the surprising history of satellite debris with the astroquarks.

How special is the Earth for having a large Moon, and what can it teach us about where to look for habitable planets? In this episode we explore new research on what kind of planets are likely to get helpful moons like our own, and then we take a look at the idea of an infinitely cycling, but not repeating universe.

Mimas, the heavily battered "death star" moon of Saturn, may harbor a sub-surface ocean of liquid water like its neighbor, Enceladus. Water may have flowed on the surface of Mars more recently than previously thought, and there's a new denizen in the menagerie of peculiar pulsars. Learn all about it and test your pulsar trivia knowledge.

The Astroquarks assemble to examine the mysterious of a star that is blocked out perhaps by a giant dust cloud. Meanwhile, the Sun is passing through a Local Bubble in the Milky Way that has triggered star formation all around us. Join us for all this, rainbow trivia, and more.

We welcome 2022 with a look at the future home of the James Webb Space Telescope - Earth's L2 Lagrange point, and an exploration of Lagrange points around the solar system. New research suggests the geysers of Enceladus may originate in a slush pool rather than the moon's ocean, and what would it mean if there were antimatter stars? All this and more can be found on this episode of Walkabout with...

One of our favorite cosmological mysteries is why there is any stuff in the universe. We're here because there was a tiny fraction more matter than antimatter created. We learn about a new observational test for one theory of why that happened, and it has to do with gravitational waves and Q-Balls! Find out what they are and learn about an odd planet and giant stellar flares closer to home.

We take a deep dive into toffee planets with The Planetary Guy, Dr. Paul Byrne, who helps us explore the myriad types of exoplanets that might be lurking out there, including some with eggshell crusts and toffee interiors. And gravitational waves have yielded another secret, confirming Stephen Hawking's Black Hole Area Theorem. Find out all about it, and black hole trivia, on WtG.

On the eve of its long-anticipated launch, we explore one of the many areas of exploration of the JWST, the early universe after the birth of the first stars and the reionization of the interstellar medium. We also take a look at a large comet showing activity beyond the orbit of Uranus, historical trivia, space news updates, and more. Join us for a walkabout the galaxy.

Scientists are creating large, quantum-fuzzy atomic nuclei with large numbers of neutrons to get clues about nucleosynthesis in the very early universe. Closer to home, the Juno spacecraft has peered hundreds of km below the Jovian cloud tops to better understand its colorful stripy system of bands and zones. And we get to say "fugacity" a lot in understanding exoplanet geological activity. Join u...

We explore an exoplanet system where the orbits of the planets are at right angles to each other. A chunk of rock trailing the Earth around the Sun may be a chunk of the Moon, and we take a look at some of the more interesting ways of getting into space and traveling long distances once we're there.

It's the first Strange Up Top episode of Walkabout with Hannah Sargeant where we explore the odd core of the Andromeda galaxy, the formation of galactic clusters, and the thermodynamics of information. Find out how the odd orbits of stars in Andromeda may the relics of an ancient black hole merger, how clusters of galaxies got their starts, and the strange consequences of the second law of thermod...

Meet Up Quark Hannah Sargeant as we explore the role of neutrinos in understanding the universe and the coupled evolution of Pluto's climate and spin state. A hypothesized sterile neutrino seems to be missing, extending the puzzle of dark matter. Catch up on all this and some truly odd balloon historical trivia, space news, and more.

Almost all exoplanets have been discovered in our local neighborhood of the Milky Way, with a few exceptions due to gravitational microlensing, still within our galaxy. Astronomers have likely identified the first exoplanet in a distant galaxy by it eclipsing an X-ray source. We also check in on models of cosmological inflation, and the Moon still has surprises in store. All this, trivia, sci-fi r...

So much going on: Shatner goes to space, the astroquarks ponder time travel, Tunguska may have been a near miss, free neutron decay holds the key to the universe, Fast Radio Bursts become more puzzling, and Strange Quark absolutely does not want any tortoises or any creatures at all, for that matter, to be harmed! Join us and special guest Dr. Hannah Sargeant for all this, Captain Kirk trivia, and...

The intrepid New Horizons spacecraft has discovered close binary comets in the Kuiper belt, and the Lucy mission is getting ready to explore binary trojan asteroids sharing Jupiter's orbit. It's all about small bodies, including just how late we can nuke an inbound asteroid and live to tell the tale. 

Comet 29P is on an odd, distant orbit, between Jupiter and Saturn, and like a fidgety child sent to the corner, it keeps having unpredictable outbursts. In other planetary systems, the numerous hot jupiter class of planets seem to have a uniform nighttime temperature due to the presence of clouds of rock droplets. Maybe a good name for a song: Rock Droplet? And we'll check in on the latest in Dark...

We discuss not one but two galactic civilizations (Dune and Foundation) coming to screens big and small this Fall. Life being a central part of most civilizations, we discuss some interesting new observations of biomolecules in space and review the bizarre menagerie of hypothesized exotic stars. Join us for all that and an Asimovian trivia.

Quasars, those incredibly bright and distant sources powered by supermassive black holes, may have a trick to their radiation that let's us use them as standard candles. We'll dive into that and take a dive in close to the Sun with the Parker Solar Probe to learn about its discoveries of new populations of dust in the inner solar system. Plus, impactor trivia, and how long would you want to stay i...

Light's odd way of behaving both like a particle and a wave is nothing new, but a cool new experiment shows that it's not an either/or but a continuum of gradations from wave to particle. The universe has some crazy stuff going on. We use the wave nature to take a look at an odd transient phenomenon at the core of the Milky Way and for Top quark to embarrass Strange quark at trivia.

We explore dwarf galaxies with no star formation and dwarf planets with a clue to a lurking object in the outer solar system. But first Top Quark is stumped by a non-stumper stumper, and our trivia takes us out to the largest structures in the universe. Catch up on all the latest news with the astroquarks, and have fun at the same time.