Astronomy Cast

We see the Universe in visible light with our photon detecting eyes. We can feel infrared heat with our photon detecting hands, and we get sunburns with our ultraviolet photon detecting skin (ouch). But there's a whole spectrum of photons out there, from radio waves to gamma rays that astronomers use to understand the Universe. It's time to see the whole picture.

We finally get organized enough deal with several listener questions: isn�t dark matter just regular stuff we can�t see? how can parts of the Universe be expanding faster than the speed of light? what will Betelgeuse look like when it explodes as a supernova? what�s the speed of gravity? All these and more questions are answered.

We finally get organized enough deal with several listener questions: isn't dark matter just regular stuff we can't see? how can parts of the Universe be expanding faster than the speed of light? what will Betelgeuse look like when it explodes as a supernova? what's the speed of gravity? All these and more questions are answered.

No more suspense. This week we blow the biggest stars up. Kaboom. Want more details? Then you've got to listen.

We've celebrated the birth of new stars, but the stellar lifecycle doesn't end there. Stars like our Sun will spend billions of years fusing together hydrogen and pumping out energy. And when the fuel runs out, their death is as interesting as their birth. This week Fraser and Pamela trace out this stellar evolution, and explain what the future holds for stars, large and small.

Most parents have had that uncomfortable conversation with their children at some point. Mommy, Daddy, where do stars come from? You hem and haw, mumble a few words about angular momentum and primordial hydrogen and then cleverly change the subject. Well, you don't have to

avoid the subject any longer. Pamela and Fraser describe formation of stars, large and small, in a tasteful manner, using only understandable and scientific language.

The discovery of dark energy was one of the biggest surprises in astronomy. Instead of a nice, predictable expanding Universe, acted on only by gravity, astronomers turned up a mysterious repulsive force accelerating the expansion of the Universe. Fraser and Pamela explain

the evidence for a dark energy, and a few possible theories for what could be providing this repulsive force

You hear distances all the time in astronomy. This star is 10 light-years away; that galaxy is 50 million light-years away; that Big Bang over there happened 13.7 billion years ago. But how did astronomers actually figure out how far away everything is? It's not a single measuring stick. Instead, astronomers have built up a series of overlapping measuring tools (yes, we're calling supernovae and variable stars tools), which take us from right around the corner to very ends of the Universe. Get out your ruler... no, the bigger one... never mind... just listen.

It's all relative. How many times have you heard that? Well, when you're traveling close to the speed of light, everything really is relative; especially the passage of time. This week, Fraser and Pamela give you the skinny on Einstein's Special Theory of Relativity. After listening to a few thought experiments, you too should be able to wrap your head around this amazing theory.

Dress warmly, gather some friends and family, and head outside to watch sand burn in the upper atmosphere. There's nothing like a good meteor shower. Fraser and Pamela explain this beautiful phenomenon: what causes them, the best storms and showers to watch for, and different types of meteors you might see.