Boston (U.S.) – 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. 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. Physicist Dimitar Sasselov, the Director of the Harvard Origins of Life Initiative, said the discovery, announced at the American Astronomical Society meeting in Boston, U.S., was a surprise since big planets were believed to be mostly gas, not solid rocky bodies like Earth or Mars. Sasselov told reporters at a news conference in Boston, U.S. that the scientists do not yet understand how the planet, known as Kepler-10c, formed, with a diameter of about 18,000 miles (29,000 km), 2.3 times greater than Earth’s. “A mega-Earth is a lot of solids concentrated in the same place without any gas. That is a problem because our under...