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.

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.

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.

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.

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.

We know about extinct comets and active asteroids, but now we've got something in between: dark comets, whose orbits indicate cometary activity, but we can't see it! We'll get the scoop on these interesting objects, a flare from a supermassive black hole, and a twist on the question of the age of Saturn's rings. Plus, we have our end-of-the-year rocket launch roundup, and a special astrophysical FLOD stumper for top quark Jim Cooney.

Top quark Jim Cooney explains why making big blobs is hard and how new observations are helping us understand how the universe made big immensely big blobs more commonly known as giant elliptical galaxies. Nature loves to make a disk, and we love to tell you all about the cool things nature does, including a solid state greenhouse on ancient Mars that may have produced a huge buried supply of water to create giant rivers near its south pole. Join us for this and more mind-blowing stuff. It's all part of our Walkabout the Galaxy.

It's a good news bad news story with the detection of the neutrino fog. This signal from solar neutrinos may confound our search for certain dark matter candidates, but at least we know our detectors are very, very sensitive! We also take a look at magnetic fields in the outer solar system, specifically why Uranus's magnetosphere was so weird when we visited in 1986, and what tiny grains from a near Earth asteroid may be telling us about the magnetic field four and a half billion years ago. Join us for all that, and of course space news and stupid trivia.

If you're speaking English, not Latin, do you really have to say "supernovae" instead of "supernovas"? Also, they are, in some sense, created equally: explosion of a white dwarf, but the outcomes are not all equal. You are welcome for this grammatical tangent, and please enjoy our fun discussion about weird tesserae (more Latin!) on Venus and the whole standard candle story of type 1a supernovae gets a rewrite. On this episode of Walkabout the Galaxy, you can also enjoy solar energy/spacecraft trivia, space news, and general hilarity at no extra charge.

New observations contradict earlier studies about the possibility of another belt of comets orbiting the Sun twice as far away as Pluto. We'll take a look at what's what in the outer solar system and also explore whether black holes may help explain the Hubble tension. We also play FLOD (Flyby, Land, Orbit, Destroy) and have some "how many planets" trivia.