Tau Ceti is the center of the nearest solar system that's similar to ours, an assumption made stronger by the discovery of four rocky super-Earths orbiting the star just 12 light years away. Two of the four planets are in the habitable zone around the star where temperatures could be just right for liquid water, and perhaps alien life, to be present. An international team of scientists devised a new, more accurate and sensitive method of detecting planets by looking for "wobbles" in the star's movement caused by the minute gravitational tug of orbiting planets, while also better ruling out...