Question

Why do we think Europa has potential for life? What is the current proposal for finding it?

Recent data from the spacecraft Galileo has suggested the possibility of water oceans trapped several kilometers beneath Europa’s icy surface. Given the present tidal heating from Jupiter, as well as its high surface radioactivity, Europa seems to have a substantial source of geothermal energy for potential life deep beneath its surface. One way to search for the presence of life on Europa would be to utilize the drilling techniques that NASA scientists have developed through research in northern Siberia. Another method may include collecting debris deposits that are present on the Europan surface. Water or ice that may have flowed through the cracks in the ice to the surface may have provided a safe harbor for deposits that may include organic material. The most relevant future technique probably comes to us from the drilling research near Lake Vostok, the largest underground lake beneath Antarctica’s frozen surface. Since the lake’s discovery in 1996 by seismic tools, drilling has gone slowly while procedures are worked out to keep the lake pristine. No one has yet seen or sampled the ancient lake--the deepest ice sample is from 100 meters (328 feet) above the liquid surface--nor is anyone sure why it is liquid, hence the scientific curiosity. Such experience will prove invaluable in designing future missions to Europa, providing lessons in how to drill through large quantities of ice, sample liquids, and search for possible life on the Jovian moon. More can be found at http://www.space.com/scienceastronomy/planetearth/extremophiles_lakevostok.html Anna Lee Strachan, NASA Astrobiology Institute
May 1, 2002