Astronomy Cast

Episode 35: Questions Show #4

We know there's matter, and we know there's anti-matter. If there's dark matter, is there an anti-dark matter? How come gravity can escape from a black hole? Do black holes capture dark matter? Can a moon have a moon? Can a planet have two stars? If you've had any of these questions, you'll want to listen to this week's show.

Episode 34: Discovering Another Earth

What a week! Astronomers announced the discovery of an Earth-sized planet orbiting the nearby star Gliese 581. We talk about the technique used to discover the planet, the possibilities of finding even smaller planets, and what the future holds for finding another Earth.

Episode 33: Choosing and Using a Telescope

Buying your first telescope can be a nerve-wracking experience filled with buyer's remorse. This week we discuss the basics of purchasing your first binoculars and telescope. What to look for, how to clean older equipment, and how to use it for the first time. Let's make sure your first investment in this wonderful hobby is money well-spent.

Episode 32: The Search for Neutrinos

Trillions of neutrinos are produced in our Sun through its nuclear reactions. These particles stream out at nearly the speed of light, and pass right through any matter they encounter. In fact, there are billions of them passing through your body right now. Learn how this elusive particle was first theorized and finally discovered.

Episode 31: String Theory, Time Travel, White Holes, Warp Speed, Multiple Dimensions, and Before the Big Bang

We get questions every week about string theory and topics popularized by science fiction. Here's the problem. There's just no evidence. Each of these is based on wonderful and well-formed mathematical equations, or wishful thinking, but they're very hard (if not impossible) to test in the real Universe.

Episode 30: The Sun, Spots and All

It's Spring in the Northern Hemisphere, and that means the Sun is back. But it's more than just a free heat lamp for your garden, it's an incredible, dynamic nuclear reaction complete with flares, coronal mass ejections, twisting magnetic fields and the solar wind. Put in your headphones, head outside and enjoy the sunshine while you listen to this week's podcast.

Episode 29: Asteroids Make Bad Neighbors

This week we're talking about asteroids. And not just any asteroids, but Near Earth Objects. How do astronomers find these things, why are they buzzing around the Earth, what are the chances we'll actually get hit, and what would happen if we did get hit? How could we stop them?

Episode 28: What is the Universe Expanding Into?