Walkabout the Galaxy

That interstellar comet appears to have gotten its odd behavior from the natural rocket effect of hydrogen gas being released near the Sun and not, sadly, alien rocket technology. The universe is still a cool and interesting place, though, and a new clever measurement of stars orbiting black holes shows evidence for a pile-up of dark matter around the black holes, giving us another way to study this mysterious stuff.

Compelling evidence for recent (1990's!) volcanic activity on Venus has been un-Earthed, or rather un-Venused, by Robert Herrick through analysis of Magellan radar data. A volcanic vent seems to have roughly doubled in size in 1991. We discuss the difficulties of these observations and the implications for future missions. We also take a look at the role of supermassive black holes in controlling star formation in galaxies and have a numerical Top quark trivia. Warning: this episode gets off to a bit of a silly start, so jump ahead to the 24-minute mark if you want to get straight to Venus!

What time is it on the Moon? It turns out the answer to that is not as easy as just lining it up with a time on the Earth. Worse, it's not even that obvious what time it is on the Earth. That's just one of many topics we explore in this episode, including a discovery that the Milky Way is much larger than previously thought, and tracing water molecules from the interstellar medium step by step into that cool glass you have with dinner. Join us for all that, time trivia, and more.

Learn about active asteroids and how the DART mission kind of turned an asteroid into an active asteroid, how impacts into Mercury have given it a dust trail, and we speculate about what might happen if Europa came to Earth. See title for conclusion! It's all about asteroids and dust and impacts on this episode of Walkabout.

Astronomers have sighted a supermassive black hole ejected from its host galaxy and creating a wake of stars from intergalactic gas. And if that wasn't enough to blow your mind, closer to home we've seen organic molecules in the material returned from the surface of a near Earth asteroid. Join us for all this, a weird exoplanet, Apollo program trivia, and some surprising tangents.

Where would you go and what would you bring with you if you could explore any object in the universe? Our cosmologist Jim Cooney wants to look for aliens underneath Europa's icy shell. This shell's complicated fractures may owe something to a new form of ice discovered in a delightfully simple experiment. Further out, a dwarf planet beyond Neptune has a ring unlike any we've seen before, and a delightfully complicated experiment may explain the origin of cosmological magnetic fields.

Neutrinos are slippery little buggers, and a new experiment is tightening the net to pin down their itsy-bitsy mass. Closer to home, the Earth's core is a complicated system with changing rates of rotation. We also take a look at the peculiar rings of a distant cometary body, Chariklo, thanks to a new observation by JWST. Join us for all the space news and Mars rover trivia.

Scientists have created a simulation of a wormhole in a quantum computer. Top quark helps us understand the significance of this as well as reminds us what the heck a wormhole is anyway. In planetary science, collisions may once again come to the rescue to help explain a mystery. This one is the odd gap in exoplanet sizes. And Down quark gives us an update on the Lucy mission to the Trojan asteroids and its sticky solar panel. Join us for all this, telescope trivia and more.

Our own solar system is lacking in one of the most common types of planet, the Super Earth. These large rocky planets have a cookie-cutter characteristic that may be explained by the evolution of stuff in a forming system's disk. Speaking of disks, a mystery about the Milky Way its family of satellite galaxies seems to have been solved. Discover all this with updates from JWST, Artemis, a look ahead to NEO Surveyor, rocket trivia, and a cosmological stumper with your hosts, the astroquarks.

Top quark Jim Cooney rejoins the crew and gives us a deep dive into the breakthrough in nuclear fusion at the National Ignition Facility. Mars rover Perseverance is busy storing samples of Mars for a future mission to bring home, and the Sun may have a 17-year cycle in addition to the well-known 11-year cycle. Ring in the new year with the astroquarks to learn about all this, comet trivia, and more.