March 19, 2015
The Hidden Ocean of Europa: Future exploration and prospects for life
Robert T. Pappalardo
Senior Research Scientist
NASA’s Jet Propulsion Lab
Lobby adjacent to McMurtry Auditorium
McMurtry Auditorium, Duncan Hall
Jupiter’s moon Europa tops a very short list of worlds in our solar system that could possibly support life today. This is because Europa may have an internal ocean of liquid water, plus the chemistry and energy life needs to exist. Europa orbits the giant planet Jupiter in the cold reaches of the outer solar system, where its icy surface forms a rock-hard crust. But a bizarre surface tell us Europa is warm inside, with a liquid water ocean about 12 miles (20 km) below. Spacecraft images show bizarre ridges and cracks crisscrossing Europa and jumbled, blocky areas that include frozen, briny water. There are few large impact craters, indicating a relatively young surface, repaved in the last 60 million years. Recent images from the Hubble Space Telescope of Europa show that giant plumes of water may occasionally spew into space. Europa’s ocean is so intriguing because similarly hostile environments in Earth’s deep oceans are teeming with life.
NASA is currently planning a robotic mission to search for water and evaluate Europa’s potential for life. The mission would investigate Europa’s icy crust, probable ocean, chemistry, and geology. It would also scout out sites for a possible future landed mission. Europa may hold answers to one of humanity’s most fundamental questions: Are we alone in the universe?
Robert T. Pappalardo is a senior research scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California. He is currently the Pre-Project Scientist for the Europa Clipper mission concept and has served as the Project Scientist for the Cassini Equinox (first extended) Mission at Saturn. He has served as a member of the National Research Council’s Space Studies Board, and he is a recipient of NASA’s Exceptional Service Medal. Pappalardo’s research focuses on processes that have shaped the icy satellites of the outer solar system, especially Europa and the role of its probable subsurface ocean.