Ep. 215: Light Echoes
Just as sound can echo off distant objects, light can echo too. And the echoes of light bouncing off stellar remnants, black hole accretion disks, and clouds of gas and dust provide astronomers with another method of probing the distant cosmos.
Ep. 214: Space Tourism
Have you ever wanted to go to space, but lacked the… everything… to be an astronaut? A whole new industry of space tourism will take you where you need to go. There are new companies offering zero-G flights, sub-orbital flights, and there have even been paying customers who have gone into orbit. Is this going to be space travel for the rest of us?
Ep. 213: Supermassive Black Holes
It’s now believed that there’s a supermassive black hole lurking at the heart of every galaxy in the Universe. These monstrous black holes can contain hundreds of millions of times the mass of our own Sun, with event horizons bigger than the Solar System. They’re the source of the most energetic particles in the Universe, the brightest objects in the Universe, and the place where the laws of physics go to get mangled.
Ep. 212: GPS Navigation
Last week we talked about the old way navigators used to find their way around the planet; by looking at objects in the sky, and doing some tricky math. The new navigation system, of course, is the Global Positioning System, and it helps you find your spot on the planet with amazing accuracy. Let’s see where the system came from, and how it works.
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. 210: Mars Exploration Rovers
The twin Mars Exploration Rovers, Spirit and Opportunity, have been crawling around the surface of Mars since early 2004 – years longer than they were expected to live. And what they have discovered there on Mars has given scientists their best understanding of Martian geology over the last few billion years. Let’s investigate these amazing rovers and their ongoing mission.
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.