After Pluto lost its planethood, we were down to 8 planets. But there’s growing evidence of another world (or worlds) out beyond the orbit of Pluto. Is Planet 9 out there and how will we find it? Could there even be a Planet 10?
Ep. 614: Centaurs, Comets and Asteroids
There are asteroids and there are comets. But there’s an entirely separate class of objects called centaurs. But instead of half-human, half-horse, imagine an object that’s half comet, half asteroid but 100% interesting.
Ep. 613: Pluto’s Demotion: 15 Years Later
Astronomy Cast more than 600 episodes ago. Are there any updates? Does Pluto have a chance of regaining planethood again?
Ep. 609: The Benefits of Volcanoes
Volcanoes can be some of the worst natural disasters we can experience here on Earth, but life wouldn’t even exist without them. What are volcanoes good for anyway?
Ep. 608: NASA Perseverance – The First 100 Days
As you all know, Pamela refuses to talk about any missions which aren’t actually doing science. Well, Perseverance has crossed the line, from fantasy to an actual working rover, scooping regolith and yeeting helicopters. What has the rover accomplished in its first 100 days?
Ep. 607: InSight and Marsquakes
Mars is cold and dead today, but the massive volcanoes tell us what the planet used to be like, millions and even billions of years ago. But how volcanically active is the planet today? That’s what NASA’s Mars InSight lander is there to figure out.
Ep. 600: Looking Ahead
Today, we gaze into the future of space and astronomy. What upcoming missions and events are we excited about?
Ep. 599: Zodiacal Light
Pamela has told us in the most flowery terms about the diffuse dust across inner solar system. Leftover from the formation the inner planets. Well, it turns out, she was wrong. Super wrong. Time to update.
Ep. 595: Planet Hunting (Updated)
This is going to be another one of those evergreen topics, where we come back to again and again. Finding planets. Every time we talk about this now, it seems like we’ve gained thousands of new planets. Well buckle up, new techniques will grow that by tens of thousands and even millions.
Ep. 594: Juno – Primary Mission Highlights
Pamela’s always loathed to talk about spacecraft until the mission’s in space and the science is rolling. NASA’s Juno mission just received a mission extension, adding Jupiter’s moons to the menu. Now, finally, we can talk about Juno.
Ep. 590: Lunar Hazards: Dust, Radiation, and More
2024 can’t come soon enough. You know, that’s the year when humans will set foot on the Moon again. Don’t you roll your eyes. That’s the plan. Well, unless the plan changes. But my point is, explorers going to the Moon will need to be concerned about all kinds of hazards, like dust, radiation and gigantic moon worms.
Ep. 589: Lunar Resources: Water (Update) & Other Volatiles
We’ve talked about water on the Moon many times here on Astronomy Cast, but there have been a bunch of big updates, thanks to new research from NASA and others. Today we’re going to give you an update on the state of water on the Moon and the plans to take advantage of it.
Ep. 588: Lunar Resources: Lava Tubes
All eyes are on the Moon. We’re going back, this time to stay… right? One of the best resources on the Moon will be the lava tubes that crisscross the subsurface of the Moon. These can provide protection from space, and a look into the geologic history of the Moon. And they can be enormous.
Ep. 584: Sample Return Missions from Asteroids
With a sample of asteroid Bennu firmly inside OSIRIS-REx’s return capsule, it’s time to bring this treasure home so scientists can study the composition and history of the space rock. But it’s not the only sample return mission out there, with Japan’s Hayabusa2 mission also bringing asteroid debris home. Today, let’s talk about the missions and what we’ve learned so far.
Ep. 578: Life on Venus?!?
Have you heard the big news? Of course you have, evidence of phosphine on Venus which could be a biosignature of life on our evil twin planet. There have been a lot of surprising stories about Venus, so let’s get you all caught up.
Ep. 577: Mars in Opposition
Every two years or so, Mars lines up nicely with the Earth. It only takes two minutes to communicate with rovers, you can see the polar ice caps in a small telescope, and it’s the best time to send spacecraft to the red planet.
Ep. 570: Discovering Comets
Discovering comets is one of the fields that amateurs can still make a regular contribution to astronomy. But more and more telescopes are getting found by spacecraft, automated systems and machine learning. This week, we’ll talk about how comets are discovered and how you can get your name on one.
Ep. 564: Mini Moons
Last month astronomers announced that they had detected a tiny asteroid that had been captured by the Earth’s gravity well and had been sharing our orbit for a few years. Today, let’s talk about the smallest moons in the Solar System.
Ep. 544: Weird Issues: Biosignatures
Once again, another place where the Universe is going to make this difficult for us. Proving, once and for all that there’s alien life on another world. It should be straightforward, look for biosignatures, but it looks like there are natural sources that could explain almost any chemical we could hope to search for.
Ep. 540: Weird Issues: How Do (or Don’t) Planets Form?
As astronomers started to discover planets orbiting other stars, they immediately realized that their expectations would need to be tossed out. Hot jupiters? Pulsars with planets? We’re now decades into this task, and the Universe is continuing to surprise us.
Ep. 539: Weird Issues: Why We Don’t Know the Age of Saturn’s Rings
How old are Saturn’s rings? They could be brand new, or they could be as ancient as the Solar System itself. Planetary scientists thought they knew the answer thanks to new data from Cassini, but new ideas are calling even that into question.
Ep. 538: Asteroids: Rubble piles of the Solar System
Thanks to all the work from Hayabusa 2 and OSIRIS-REx, astronomers are getting a much better look at the smaller asteroids in the Solar System. It turns out, they’re piles of rubble… but fascinating piles of rubble. Let’s talk about what we’ve learned so far.
Ep. 522: Judging Age & Origins, part 1 – Earth Rocks
People always want to know how old everything is. And more specifically, they want to know how we know how old everything is. Well, here at Astronomy Cast, it’s our job to tell you now only what we know, but how we know what we know. And today we’ll begin a series on how we know how old everything is.
Ep. 516: Polar Vortices
It’s cold right now. Okay, fine, here on Vancouver Island, it’s actually pretty warm. But for the rest of Canada and big parts of the US, it’s terrifyingly cold. Colder than Mars or the North Pole cold. This is all thanks to the break up of the polar vortex. What are polar vertices, how do they form, and where else to we find them in the Solar System?
Ep. 505: Seismology
We’re always interested in the surface features of the planets and moons in the Solar System, but that’s only skin deep. It turns out, these worlds have an interesting inner life too. Thanks to the science of seismology, we can peer into our planet and learn how it works… inside. And we’re about to take that technology to Mars.