Astronomy Cast Full Raw Feed

Ice is ice, right? You know, what you get when water freezes. Well, maybe here on Earth. But across the Universe, water can be squeezed together at different temperatures and pressures, leading to very different structures. Today we'll talk about the different forms that ice can take.

The asteroid apocalypse is one of those existential crises that keep astronomers up at night. But the DART mission showed us that we can push an asteroid off its trajectory if we have enough warning. Today we'll talk about how humanity is building early warning systems to give us time to respond to a dangerous asteroid.

If you're in dark skies and look up, you're certain to see a satellite. Lots of them. But how can you know which one you're seeing, and how can you improve your chances of a sighting? Today we'll talk about how to see satellites, or avoid seeing them.

We've talked about the rising problem of space junk. Okay, we know it's an issue. So what can be done about it? Today we'll talk about ideas to remove space junk, making sure space is open to use for the centuries to come.

Last week we talked about the laws that govern space exploration. This week the rubber hits the road. What are the consequences for actually breaking these rules? Are they really going to stop anyone?

Streamed live on Feb 13, 2023. The Universe was inaccessible for most of human history, but the first tentative steps to space in the 20th Century made humanity realize that science fiction was becoming science reality. New rules would have to be written to govern how we used this limitless expanse. Today we'll talk about the Outer Space Treaty of 1967.

It's been over 20 years since astronomers first discovered that the expansion of the Universe is accelerating thanks to dark energy. And in these decades, astronomers still don't have much evidence for what could be causing the increased expansion rate. Maybe there's something else going on to explain it.

Astronomers have made extremely accurate measurements of the expansion rate of the Universe and come up with different results. And the error bars for the observations don't overlap, so there's something strange going on. What's the answer and how can the Crisis in Cosmology be resolved?

Astronomers came together in January to present their newest research. And not surprisingly, the winter AAS meeting was heavy on news from the James Webb Space Telescope. What were some of the new results that were announced?

Well, we did it. We made it to episode 666, an auspicious number to be sure. What can we do to celebrate this accomplishment? An episode all about things in the Universe that have been named after mythological people and places in the underworld!

The Cosmic Microwave Background Radiation tells us so much about the Universe. After that era, the Universe went dark. Then, as gas pulled together into the first stars and eventually galaxies, light returned, beginning the Age of Reionization.

The Sun is a third-generation star, polluted with metals from long-dead suns. Astronomers have also discovered second-generation stars, with very low metallicity. But theories suggest there must be a first generation, with stars made from only pure hydrogen and helium. Can we ever find them?

We generally save our stargazing suggestions for the summer, when it's warmer in the northern hemisphere. But you're tough, you can handle a little cold. And it's worth it because there are some wonderful things you can see in the night sky this time of year.

Last week we talked about the missions we're saying goodbye to. This week, we're going to talk about some upcoming missions to say hello to. Some are brand new ideas, others are, uh, recycled.

It's always sad to say goodbye, but when we send our robotic emissaries out into the cosmos, it's just a matter of time before they shut down. Today we're going to say goodbye to a few missions which have reached the end of their lives… But they were very good robots.

Moons orbit planets, planets orbit stars, stars orbit within galaxies. It's orbits all the way down. But occasionally objects can receive a powerful kick that sends them on a journey, never to return.

Streamed live on Nov 8, 2022. Light pollution is big problem and it's only getting worse. Not just near cities, but everywhere thanks to increased satellite constellations. How bad is the problem, and how can we fix it?

Streamed live on Oct 31, 2022. We're recording this episode on Halloween, so how could we resist but take advantage of this opportunity. Space is already terrifying enough, you know, with the vast endless emptiness, the incomprehensible mysteries, and the uncaring coldness. But here are some scary stories to spook it up a notch.

Space is a big place, with lots of galaxies, stars, planets, moons, and that means a lot of names. So how do astronomers name stuff, like comets, asteroids, exoplanets, craters?

Streamed live Oct 3rd. This week we saw the incredible image of DART smashing into asteroid Dimorphous. Beyond avenging the dinosaurs, what can we learn scientifically from this and other asteroid/comet impact missions

Streamed live on Sep 26, 2022. It's been about 65 years since the Soviets launched the first orbital satellite into low Earth orbit: Sputnik 1. Now there are thousands of satellites in orbit, with tens of thousands on the way. Let's look at the impact that Sputnik had on the history of spaceflight.

To battle climate change, we'll need to rapidly move to carbon-free sources of energy. But this technology isn't a free lunch. They require metals, generate waste and deplete the environment. What's the best way to balance this shift?

Climate change is on our mind these days with increasing wildfires, droughts and floods. What are the variables that play into a planet's changing climate and what can this teach us about the search for habitable planets in the solar system and across the Milky Way?

Last week we talked about how single-use rocketry has changed over time, and the role it still plays in launching payloads into orbit and beyond. Today we'll address the stainless steel elephant in the room and talk about the shift to reusability.

Season 16 opener. On the day that we're recording this, NASA's Space Launch System is about to blast off. But everyone is expecting it'll be delayed to October. When it does launch, it'll be the most powerful rocket on Earth. Well, until Starship blasts off. So are we about to see the end of single-use rockets and enter the era of reusable rocketry?