Astronomy Cast

Have you ever heard an astronomer utter these words? Oh be a fine girl and kiss me. They’re not being romantic, they’re trying to remember the different ways to organize stars, as detailed nicely on a Hertzsprung–Russell diagram. Let’s learn what all those letters mean, and what differentiates a type O star from a type G.

The Sun, Moon, stars and planets are visible to the unaided eye, and so they have been visible to astronomers since before recorded history. Some of the earliest records we do have tell us what the ancient astronomers thought about the heavens, and how they used the changing night sky in their daily lives.

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.

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?

AstronomyCast 211: Celestial Navigation

AstronomyCast 210: The Mars Exploration Rovers: Spirit & Opportunity

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 better 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.

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.

AstronomyCast 209: Exotic Life

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.