Around forty years ago, a Voyager spacecraft captured the first closeup images of Europa, one of Jupiter’s 79 moons, revealing brownish cracks slicing the moon’s icy surface, which give it the look of a veiny eyeball. Missions in the decades since have gathered enough additional data about Europa to make it a high-priority target of investigation in NASA’s search for life. What sets this moon apart from the others is the possibility that it may possess all of the ingredients necessary for life.
Scientists have confirmed evidence that one of these ingredients, liquid water, is present under the icy surface and may sometimes erupt into space in huge geysers. That’s right, an international research team led out of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, has discovered water vapor for the first time above Europa’s surface, and they measured it by peering at Europa through one of the world’s biggest telescopes in Hawaii.
Essential chemical elements (carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur) and sources of energy, two of three requirements for life, are found all over the solar system. But the third — liquid water — is somewhat hard to find beyond Earth. While scientists have not yet detected liquid water directly, we’ve found the next best thing: water in vapor form,” said Lucas Paganini, a NASA planetary scientist who led the water detection investigation.