Now that we’ve discovered thousands of exoplanets, we’re learning more and more about what kinds of planetary systems there are out there across the Universe. Are planets like Earth unique or totally rare?
Ep. 642: Is the Sun… Normal?
We’ve always assumed that we lived in a perfectly normal system with a normal star and normal planets. It’s all… normal. But with our modern understanding of billions of stars, just how normal is our Sun, anyway?
Ep. 628: The Sun Revisited
Once again, it’s time to take a look at the Sun. You know, ongoing thermonuclear explosion of fusing hydrogen that’s right over there. Fortunately, there’s a fleet of spacecraft and ground observatories ready to give our best ever view of the Sun.
Ep. 627: Mercury Revisited
It’s been about a thousand years since we last looked at Mercury, so we figured it’s time for an update. What new things have we learned about Mercury, or even new questions? Fortunately, there’s a mission on the way to help get us some answers.
Ep. 626: Terrestrial Planets — Mercury, Venus, Earth, and Mars
We continue our refreshed tour of the Solar System, checking in on the inner terrestrial planets: Mercury, Venus, Earth and Mars. What have we learned about their formation, evolution and what they might tell us about other planets in the Universe?
Ep. 624: Small Rocky Bodies (Including Phobos and Deimos)
We’ve talked about the icy objects of the Solar System, today let’s talk about space rocks. There’s a surprising variety of rocky material in the Solar System, and each object has a story to tell about the history and formation of the planets, moons and other rocky bodies.
Ep. 623: NEOS: Concern or Nah?
Are asteroids dangerous? Just ask the dinosaurs, and they’ll tell you a sad story of fiery death. It turns out we’re in a shooting gallery of space rock and metal, and somewhere out there there’s one with our name on it. Should we be worried or are the risks so minimal to be irrelevant?
Ep. 622: Rocky Moons and Giant Asteroids
A rock is a rock is a rock, right? Across the Solar System there are giant rocky asteroids and even rockier moons. What’s the difference between these two families of objects, and where did they come from?
Ep. 621: Gas Giants
For the longest time, the only gas giant planets we knew about were Jupiter and Saturn. But now in the age of extrasolar planets, astronomers have discovered thousands of gas giants across almost as many star systems. What new discoveries have been made about gas giants, both here in the Solar System and across the Milky Way?
Ep. 620: Why Getting to the Outer Worlds is So Difficult
Good news! Over the next few years, we’re going to see a flotilla of new missions headed to Jupiter and Saturn. Why aren’t we seeing more missions to the outer planets, like Uranus and Neptune? It turns out, those places are far away. Today let’s talk about the challenge of exploring the outer Solar System.
Ep. 619: Icy Moons and Dwarf Planets
The outer Solar System is far enough from the Sun that water doesn’t get blasted away into deep space. In this icy realm, there are many worlds with vast quantities of water ice. Today let’s look at the icy outer moons and dwarf planets.
Ep. 618: Ice Giants
We’re learning more and more about the outer planets of the Solar System. Uranus and Neptune are ice giants, filled with water and other volatiles that we’d consider ice if it was here on Earth. What’s inside these worlds, and what could we expect to find across the Milky Way?
Ep. 615: Planet 9
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. 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.