After determining that the ocean beneath the icy surface of Saturn’s moon Enceladus has roughly the same pH as Windex or soapy water — an indication that the water has been in contact with rock, creating potentially life-friendly chemistry — scientists are moving on to the trickier hunt for evidence of hydrothermal venting.
The data comes from NASA’s Saturn-orbiting Cassini spacecraft, which in October made its deepest dive into plumes of vapor and ice jetting off the southern polar region of Enceladus, a 310-mile wide moon that has emerged as a top contender in the search for life beyond Earth.
“This is really is a world with a habitable environment in its interior,” planetary scientist Jonathan Lunine, with Cornell University, said at the American Geophysical Union conference in San Francisco.
Early analysis of Cassini’s 30-mile high pass over Enceladus on Oct. 28 indicates that the moon’s subsurface ocean, which is believed to be the source of the plumes, has telltale chemical fingerprints of water that has interacted with rock.
“This is remarkably high pH solution,” said geochemist Christopher Glein with the University of Toronto and the Southwest Research Institute in Boulder, Colorado.
“How did it get that way? We think that what happened on Enceladus, and which could still be happening today, is that there were geochemical reactions between magnesium and iron-rich rocks in Enceladus’ core reacting with ocean water. Those reactions led to the high pH,” Glein said.
The process, known as serpentinization, has been found on Earth, such as in Lost City, a…