Alien Planet

December 5, 2011 - 3:52 PM
This undated handout artist rendering provided by NASA shows Kepler-22b, a planet known to comfortably circle in the habitable zone of a sun-like star. It is the first planet that NASA's Kepler mission has confirmed to orbit in a star's habitable zone -- the region around a star where liquid water, a requirement for life on Earth, could persist. NASA has found the new planet outside our solar system that's eerily similar to Earth in key aspects. Scientists say the temperature on the surface of the planet is about a comfy 72 degrees. Its star could almost be a twin of our sun. It likely has water and land. (AP Photo/NASA/Ames/JPL-Caltech)