Earth's magnetic field does more than keep everyone's compass needles pointed in the same direction. It also helps preserve Earth's sliver of life-sustaining atmosphere by deflecting high energy particles and plasma regularly blasted out of the sun. Researchers have now identified a prospective Earth-sized planet in another solar system as a prime candidate for also having a magnetic field -- YZ Ceti b, a rocky planet orbiting a star about 12 light-years away from Earth.