Scientific American has a nice little article covering an area of astronomy you probably don’t think much about: When a new extrasolar planet is discovered, how do the artists illustrate a planet they’ve never seen?
Turns out, there’s a lot of science behind the illustrations, of course. Things like planetary size determine whether the planet is a gas giant or ball of rock. Composition can determine the colors of the atmosphere, and distance from the star can give dramatic artistic visualization to an illustration. It’s all covered.
As a bonus, the article also mentions Lynette Cook as one of the artists NASA contacts to create an illustration. Check out her website for some really nice pictures. Heck, go check out the Spitzer Space Telescope’s Artist’s Conception page for even more eye candy, many wallpaper worthy.