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 off on a journey, never to return.
Ep. 657: Astronomical Naming Schemes
Space is a big place, with a lot of galaxies, stars, planets and moons, and that means a lot of names. How do astronomers name stuff, like comets, asteroids, exoplanets, craters?
Ep. 656: Smashing Asteroids for Science!
This week we saw the incredible image of DART smashing into asteroid Dimorphos. Beyond avenging the dinosaurs, what can we learn scientifically from this and other asteroid/comet impact missions?
Ep. 653: Climate Change: Looking at the Variables
Climate change is on our minds 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 across the Milky Way?
Ep. 644: Is Earth… Normal?
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. 641: Are Planets Alive?
The Earth is teeming with life, both in the upper atmosphere to kilometers underground. There’s no question that our planet has life. But is our planet itself alive? This is a question posed back in the 1970s as the Gaia hypothesis, and it got its share of criticism. Some new ideas have been proposed to bring this hypothesis to the modern era.
Ep. 633: Weirdly Habitable Places
We’ve always assumed that habitable planets would need to be like Earth; a terrestrial planet orbiting a sunlike star. But now astronomers have been discovering planets in the habitable zone around very much non-sunlike stars. What strange places could be habitable?
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. 625: End of the Year Review
We’ve reached the end of 2021, and this is the last episode of the year. Let’s look back at the big space events of the last year and talk about what we’re looking forward to in 2022.
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. 611: What is Required to Confirm Alien Life: Intelligence Edition
Last week we talked about what it’s going to take to confirm basic biological life across the Solar System and the Milky Way. This week, we’ll discuss what it’s going to take to detect intelligent life out there in space.
Ep. 610: What is Required to Confirm Alien Life: Non-sentient Edition
Are we alone in the Universe? It’s one of the biggest scientific questions we can possibly ask. And yet, with rovers on Mars, missions planned to visit Europa and Ganymede. Powerful telescopes able to detect the atmospheres of exoplanets, we’re closer than ever to finding out the answer.
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?