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Life's lucky 7: The places most likely to harbor aliens

By: Bryan Nelson on Feb. 17, 2010, 12:20 p.m.
Europa

Photo: NASA/Wiki Commons

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Europa

Europa is the sixth moon of the planet Jupiter. The moon is unique in that its surface is covered with a thick layer of ice. Although it is far away from the Sun, Europa is likely warmed internally by vents on the bottom of the ocean, which many experts believe could warm the ice, creating a liquid ocean beneath the frozen surface. That means it might be capable of supporting microbes and simple plants, as occurs at Earth's hydrothermal vents.