Narrator: This is Science Today. Direct evidence that distant planets do indeed exist was recently uncovered when one was witnessed actually passing in front of its star. Geoff Marcy is one of the astronomers from the University of California, Berkeley who made the discovery.

Marcy: This is an event in nature that we've always expected would happen and to have it actually occur was sort of stunning. When you expect something long enough and it doesn't happen, you begin to think it'll never happen and we certainly were beginning to think, well maybe this lucky transit of a planet just won't occur. But then boom! It happened out of the clear blue and so we were quite excited.

Narrator: Another discovery is that the extrasolar planets orbit in ellipses, rather than the circular motion of the planets in our solar system.

Marcy: We have to wonder whether or not indeed our solar system is unusual compared to solar systems in general. We had always thought that our solar system was a run-of-the-mill, garden-variety planetary system, but maybe in fact it's some sort of cosmic freak and that our solar system is very, very special.

Narrator: For Science Today, I'm Larissa Branin.