Our moon stabilizes Earth's axis and makes for habitable conditions; but, scientists discover, life is still possible without moonlit nights.
The Kepler Space Telescope has located a thousand new planets—two of which are similar to Earth and could, hypothetically, support life.
As it turns out, life may not be limited to orbits around sun-like stars.
One of the great mysteries: Does life exist elsewhere in the universe. Research has found that such planets may be more common, and much closer, than we think.