Size comparison of HAT-P-11b (gray) with Neptune Astronomers have detected water vapor in the atmosphere of an exoplanet, an extrasolar planet, which does not orbit the Sun. The planet is the size of Neptune and about four times the size of Earth. It orbits a star some 130 light years from Earth. HAT-P-11b’s atmosphere was also found to contain copious amounts of hydrogen. Atmospheres are telltales... 

NASA’s Dawn spacecraft heads toward the dwarf planet Ceres as seen in this undated artist’s conception released January 22, 2014. The dwarf planet Ceres, which is the biggest object in the asteroid belt lying between Mars and Jupiter, is spewing water vapor into space from its ice-covered surface, scientists say. Researchers detected plumes of water vapor, which periodically gushes from...