"Mudpods" like the one illustrated here could be the favorite prey of "gulphogs" (see previous picture) on a planet orbiting a red dwarf star, according to scientists.

Astronomers calculate that there are tens of billions of planets in the universe, many of them orbiting stars like our sun. Many astronomers say the chances are that somewhere out there, there is extraterrestrial life.

The illustration was made for the National Geographic Channel documentary Extraterrestrial, a look at what life on other worlds might really look like. Visit the Channel's Extraterrestrial Web site for a video excerpt, more images, and an interactive feature.

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