Water vapor on Jupiter moon could be from ocean under ice cover

NASA says the Hubble Space Telescope has seen water vapor over Jupiter's moon Europa, the first evidence of water plumes erupting off the moon's surface. Previous scientific observation have strongly suggested the existence of an ocean under Europa's icy crust, and while scientists are not fully certain if the detected water vapor is generated by erupting water plumes on the surface, they are confident this is the most likely explanation, NASA's Jet Propulsion Laboratory in Pasadena, Calif., reported Thursday. "By far the simplest explanation for this water vapor is that it erupted from plumes on the surface of Europa," lead study author Lorenz Roth of Southwest Research Institute in San Antonio, Texas, said. "If those plumes are connected with the subsurface water ocean we are confident exists under Europa's crust, then this means that future investigations can directly investigate the chemical makeup of Europa's potentially habitable environment without drilling through layers of ice. And that is tremendously exciting." If the plumes are confirmed it would make Europa the second moon in the solar system known to have water vapor plumes. In 2005, NASA's Cassini orbiter detected jets of water vapor and dust spewing off the surface of Saturn's moon Enceladus. Scientists say the suspect long cracks on Europa's surface, known as lineae, might be venting water vapor into space, and Cassini has seen similar fissures that host the Enceladus jets.