When the super-Earth COROT-7b was discovered in 2009, it was heralded as the rockiest, most Earth-like exoplanet (planet outside the Solar System), yet. But a new study suggests it is more like a comet. In a paper to be published in the journal Icarus, an international team of astronomers led by Alessandro Mura of the Italian Institute for Interplanetary Space Physics argue that, given the planet’s likely composition and distance from its star, COROT-7b probably loses its surface elements to space in a comet-like tail of charged particles. COROT-7b is less than twice the size of Earth and about five times Earth’s mass, and orbits a star 390 light-years away. Because its density is similar to Earth’s, astronomers hailed it as the first rocky exoplanet discovered and one of the best candidates for hosting extra-terrestrial life. - Wired