Astronomers discover type of rocky planet much bigger than Earth

BOSTON (Reuters) – Astronomers have discovered a new type of rocky planet beyond the solar system that weighs more than 17 times as much as Earth while being just over twice the size, scientists said yesterday.

The so-called “mega-Earth” circles a very old star called Kepler-10, which is located about 560 light-years away from Earth in the constellation Draco.

The discovery, announced at the American Astronomical Society meeting in Boston, was a surprise since planets that big were believed to be mostly gas, not solid rocky bodies like Earth or Mars, said physicist Dimitar Sasselov, director of the Harvard Origins of Life Initiative.