A rocky planet weighing 17 times as much as Earth has been found, surprising astronomers who expected it to be a big ball of gas. Scientists dubbed the planet a “mega-Earth” because it’s much larger than previously discovered rocky celestial bodies. The planet, sighted by the U.S. National Aeronautics and Space Administration’s Kepler spacecraft, is located 560 light years from Earth and circles a Sun-like star every 45 days, The […]