Europa's Ocean May Have Earth-like Chemistry Say NASA Scientists

Posted on May 18, 2016

Fractures on the icy surface of Europa

NASA says a new study suggests that Europa's ocean may have an Earth-like chemistry. They say this is possible even if Jupiter's moon lacks volcanic hydrothermal activity. The moon is thought to have a deep ocean of salty liquid water beneath its icy shell.

The image above was taken by NASA's Galileo spacecraft and shows linear fractures on the icy surface of Jupiter's moon Europa. Scientists at NASA's Jet Propulsion Laboratory compared Europa's potential for producing hydrogen and oxygen with that of Earth through processes that do not directly involve volcanism. The balance of these two elements is considered a key indicator of the energy available for life. The study found that on both Earth and Europa oxygen production is about 10 times higher than hydrogen production. A research paper on the study was published here in the journal, Geophysical Research Letters.

The researchers say cracks cracks in Europa's seafloor likely open up over time as its rocky interior cools over time. These cracks expose fresh rock to seawater, where hydrogen-producing reactions can take place. The researchers also say they found that modeled Europa hydrogen flux from water-rock interaction is similar to Earth's. On Europa, oxygen and other compounds that could react with hydrogen could be cycled into the ocean from the icy surface above.

Kevin Hand, a planetary scientist at JPL who co-authored the study, says in a statement, "The oxidants from the ice are like the positive terminal of a battery, and the chemicals from the seafloor, called reductants, are like the negative terminal. Whether or not life and biological processes complete the circuit is part of what motivates our exploration of Europa."

NASA is currently formulating a mission to explore Europa to determine whether it might be habitable. A website about the mission is available here. Last year NASA released this video about a possible Europa mission:



Photo: NASA/JPL-Caltech/ SETI Institute