EPOXI Team Develops New Method to Find Alien Oceans

http://www.nasa.gov/mission_pages/epoxi/alien_ocean_prt.htm

Astronomers have found more than 300 alien (extrasolar) worlds so far. Most of these are gas giants like Jupiter, and are either too hot (too close to their star) or too cold (too far away) to support life as we know it.

Sometime in the near future, however, astronomers will probably find one that's just right – a planet with a solid surface that's the right distance for a temperature that allows liquid water -- an essential ingredient in the recipe for life.

Still of EPOXI video showing Earth and the Moon.These two videos from EPOXI show the moon transiting (passing in front of) Earth. They are observed at different light wavelengths, which is why differences in details are visible. The first version uses a red-green-blue filter; the second, an infrared-green-blue. The first pictures of an Earth-like extrasolar planet will not be this detailed. Instead, the images will be more like the Voyager picture of Earth as a single point of light (below).

But the first picture of this world will be just a speck of light. How can we find out if it might have liquid water on its surface? If it has lots of water – oceans – we are in luck.