Ep. 300: What We've Learned in Almost 7 Years

We created Astronomy Cast to be timeless, a listening experience that’s as educational in the future as it was when we started recording. But obviously, things have changed in almost 7 years and 300 episodes. Today we’ll give you an update on some of the big topics in space and astronomy. What did we know back then, and what additional stuff do we know now?

Ep. 298: Space Stations, Part 3 — International Space Station

And now we reach the third part in our trilogy on space stations, with the largest vehicle ever assembled in space: the International Space Station. Launched in 1998, it now consists of 450 metric tonnes of modules, power systems and spacecraft and is regular host to a handful of astronauts from many countries.

Ep: 290 Failed Stars

If you get enough hydrogen together in one place, gravity pulls it together to the point that the temperature and pressures are enough for fusion to occur. This is a star. But what happens when you don’t have quite enough hydrogen? Then you get a failed star, like a gas giant planet or a brown dwarf.

Ep. 285 How the World Will Really End

Have you checked out the internet lately? Apparently there is some kind of rogue planet causing pole alignment and a killer solar flare that will set off a chain reaction turning the whole universe into strange-matter…. after an alien invasion.

Ep. 266: Archimedes

It’s time to look deep into history to the birthplace of modern mathematics – Ancient Greece. And the most famous mathematician of the time was Archimedes. We use many of his mathematical theories and inventions to this day; others are steeped in legend and mystery.

Ep. 257: Viking Orbiters

Spirit, Opportunity and Curiosity get all the news now, but it was NASA’s Viking Missions that gave us our first close up view of the surface of Mars. These twin missions, both made of orbiter and lander set the stage for the exploration of Mars, demonstrating that we could actually reach the surface of Mars, and study the soil up close. Today, let’s talk about the Viking Orbiters.

Ep. 256: Resolution

When it comes to telescopes, astronomers really just care about resolution: how much can you see? Your resolution defines how much science you can get done, and it depends on your gear, wavelength, and conditions. Putting a telescope in space really helps too.

Ep 254: Reflection and Refraction

Light can do some pretty strange stuff, like pass through objects and bounce off them; it can be broken up and recombined. In fact, everything we “see” is actually the end result of reflection and refraction of light. Time to understand how it all works.

Ep. 251: Messier Catalog

Have you ever looked into the sky and noticed a fuzzy blob? That’s a Messier Object, carefully cataloged by Charles Messier to make it easier to find comets. We’ll learn about the history of the catalog, Messier’s criteria and some of the prominent objects you’ll see in the sky.

Ep. 242: Torino Scale

When you hear of a looming asteroid strike, do you wonder what to do? Should you go into your underground bunker, evacuate the state, or leave the planet? Fortunately, astronomers have developed the Torino Scale – a handy measurement that incorporates both the risk of a strike with the amount of devastation.

Ep. 241: Astrophotography, Part 3: Image Processing

Time for part 3 of our tour through the hobby of astrophotography. You’ve set up your gear, taken some clear images. Now we’re going to help you turn that raw data into the kind of amazing photographs you see in books and on the web.

Ep. 240: Astrophotography, Part 2: Techniques

In the first episode, we talked about the gear you’ll need for your expensive astrophotography hobby. This week we continue our discussion, and talk about the techniques you’ll use to get those amazing photographs. Bring a hot drink, and get ready for some cold nights. But trust us, it’ll all be worth it.

Ep. 235: Einstein

What can we say about Einstein? Albert Einstein! Lots, actually. In this show we’re going to talk about the most revolutionary physicist… ever. He completely changed our understanding of time, and space, and energy, and gravity. He made predictions about the nature of the Universe that we’re still testing out.

Astronomy Cast at Dragon*Con 2011: Strange Stuff in Space

This is an impromptu episode of Astronomy Cast that we recorded during Dragon*Con 2011. Pamela was scheduled to speak with a panel about strange things in space, but she ended up being the only person there. So Fraser jumped in, and this was what we did. We mostly talked about unusual things in the Solar System, but a few things in the rest of the Universe.

Ep. 234: Lunar Phases

The Moon is a stark reminder that we actually live in a Universe filled with stars and planets and moons. The changing phases of the Moon show us the relative positions of the Earth, the Sun and the Moon as they interact with one another. Let’s learn about the different phases, the geometry of the whole system, and some of the interesting science wrapped up with our fascination of our only natural satellite.

Ep. 228: Giovanni Cassini

Another two parter, coming at you. This week we talk about the Italian astronomer, Giovanni Domenico Cassini, best known for discovering Saturn’s moons and the biggest division in Saturn’s rings. Cassini made many other important discoveries in the Solar System, and in the fields of physics and astronomy.

Ep. 226: Weather

How’s the weather? Maybe a better question is… why’s the weather? What is it about planets and their atmospheres that create weather systems. What have planetary scientists learned about our Earth’s weather, and how does this relate to other planets in the Solar System. What is the most extreme weather we know of?

Ep. 224: Orion

Most people know how to find two constellations: the Big Dipper, and Orion the Hunter. You can teach a small child to find Orion, and at the right time of year, they’ll find it in seconds. There’s so much going on in this spectacular constellation, from the star formation in the Orion Nebula to mighty red supergiant Betelgeuse, ready to explode. Let’s learn about the history and science of the constellation Orion.

Ep. 220: Mass Extinction Events

The Earth seems like a safe place, most of the time. But we have evidence of terrible catastrophes in the ancient past. Times when almost all life on Earth was wiped out in a geologic instant. What could have caused so much devastation? And will something like this happen again?

Ep. 211: Celestial Navigation

Before there was GPS, navigators had to rely on the Sun and the stars to find their way around the Earth. It’s easier than it sounds, if you’ve got the right instruments, clear skies, and a really accurate clock. Let’s examine the history of celestial navigation, learn about the different methods, and then give you some practical ways that you can go out and learn how to do this for yourself.

Ep. 209: Exotic Life

We don’t like to cover news on Astronomy Cast, but sometimes there’s a news story that’s interesting, complicated, and rapidly unfolding – and it happens to cover an area that we haven’t talked much about. So today we thought we’d talk about the discovery of arsenic-based life, and exotic forms of life in general. Maybe we need to redefine our definition of life. Or maybe we just got introduced to some distant cousins.

Ep. 208: Spitzer Space Telescope

Last week we talked about Lyman Spitzer, and this week we’ll take a look at the orbiting observatory that bears his name: the Spitzer Space Telescope. Designed to see into the infrared spectrum, Spitzer has returned images of objects that were previously hidden to astronomers by thick shrouds of gas and dust.

Ep. 207: Lyman Spitzer

Time for another action-packed double episode of Astronomy Cast. This week we focus on the Lyman Spitzer, a theoretical physicist and astronomer who worked on star formation and plasma physics. Of course, this will lead us into next week’s episode where we talk about the mission that bears his name: the Spitzer Space Telescope.

Ep. 206: Fission

Last week we talked about fusion, where atoms come together to form heavier elements. This week, everything comes apart as we talk about nuclear fission. How it occurs naturally in the Universe, and how it has been harnessed by science to produce power, and devastating weapons.

Ep 198: How is a Space Mission Chosen?

Space missions are expensive to build and launch, so there’s a lot of planning that goes into choosing exactly what’s going to be shot into space. Space scientists and engineers recently went through the process of deciding on their science goals, so we thought we’d spend an episode explaining how this works, and how the next generation of spacecraft and telescopes will be selected.

Recent Episodes