Thought To Be Habitable, Jupiter's Moon “Europa” Seems To Lack Oxygen

Europa, one of Jupiter's enigmatic moons, has long fascinated scientists with its potential to harbor life beneath its icy surface. Now, a groundbreaking study sheds light on a crucial aspect of Europa's habitability: the production of oxygen on its frosty exterior.

Published in the journal Nature Astronomy on Monday, the study unveils the findings of astronomers who utilized data from NASA's Juno mission to investigate the generation of oxygen molecules at Europa's surface. Led by Jamey Szalay, a plasma physicist at Princeton University, the research offers valuable insights into the mechanisms behind oxygen production on the moon.

According to the study, Europa's icy crust acts as a "lung," with charged particles from space bombarding the surface and breaking down frozen water into hydrogen and oxygen molecules. While this process differs from photosynthesis on Earth, it presents a potential source of oxygen that could permeate Europa's subsurface ocean, possibly fostering conditions conducive to life.

Dr. Szalay's team analyzed data collected by the Juno orbiter's Jovian Auroral Distributions Experiment (JADE) instrument as it traversed Europa's plasma-rich environment. By focusing on hydrogen levels, which serve as an indirect indicator of oxygen production, the researchers estimated that Europa generates approximately 13 to 40 pounds of oxygen per second at its surface.

While this rate falls within the lower end of previous estimates, astronomers remain optimistic about Europa's habitability potential. Fran Bagenal, a planetary scientist at the University of Colorado Boulder, emphasized that the exact amount of oxygen needed to sustain life remains uncertain, suggesting that the study's findings do not diminish Europa's prospects.

Despite the significant insights gained from the study, numerous questions remain unanswered. For instance, astronomers are still uncertain about the fate of oxygen molecules once they are produced at Europa's surface. Additionally, the study does not address the extent to which oxygen permeates the icy crust to reach the subsurface ocean.

While Juno's mission has concluded its close flybys of Europa, upcoming missions such as the European Space Agency's Jupiter Icy Moons Explorer and NASA's Europa Clipper are poised to provide further insights into Europa's mysteries. These missions aim to confirm the existence and properties of Europa's subsurface ocean, offering invaluable opportunities to unravel the moon's secrets.

As scientists continue to unravel the mysteries of Europa, Dr. Szalay expressed optimism about the wealth of data yet to be analyzed from Juno's flybys. He emphasized the importance of ongoing research in understanding Europa as a complex celestial body and its potential implications for the search for extraterrestrial life.