Walkabout the Galaxy

A 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!

Analysis of the samples returned from the asteroid Bennu have revealed surprising assemblages of minerals that put new constraints on the origin of the solar system. And once Top Quark Jim Cooney stops giggling, he tells us about the discovery of an itsy-bitsy galaxy, if you can call it that, orbiting the Milky way. It has only dozens of stars, plus, probably some dark matter. Join us for these surprising discoveries, space news updates, variable star trivia, and a generally good time.

We peer back in time both to the murky history of our own solar system and to the dark ages of the universe. The JWST has confirmed that dwarf galaxies were the first to illuminate the universe, putting an end to the dark ages that followed the cooling after the big bang. In our own corner of the universe, new research highlights how nearby stars can lead to dramatic changes in our planet's climate by affecting the Earth's orbit. Join us for all this, nerd news, space news, and eclipse trivia.

One of only a handful of recurrent novas, white dwarf stars that undergo a periodic explosive brightening as they accrete material from a neighboring star, is showing signs that it may be ready to blow sometime in 2024! Visible in the northern hemisphere, T CrB may become visible to the naked eye for a few days this year, repeating a cycle that occurs roughly every 80 years. Closer to home, new analysis of structures and composition on Mars' Tharsis bulge reveal what may be a previously unknown and now-extinct volcano. Join us for explanations, space news, spaceflight trivia and more.

The presumed metallic asteroid Psyche gets a new look before the spacecraft of the same name gets there in 2029, and it reveals different spectral characteristics than were observed in previous studies. We discuss the mystery of metallic asteroids and what we might see at Psyche. Top quark educates us about the largest binary black hole system, with two supermassive black holes orbiting each other from an ancient galactic collision. Join us for all this, space news, and tiny rocket trivia.

Saturn's so-called Death Star moon Mimas may harbor a global subsurface ocean based on analysis of Cassini data of the tiny moon's orbit and rotation. And in the distant universe, what was previously thought to be a run-of-the-mill star in our own galaxy turns out to be a quasar thousands of times brighter than our entire galaxy itself. Join us on our 350th episode for breakthroughs in astronomy near and far, space news, sci-fi trivia, and more.

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.