NASA’s Juno spacecraft has instantly measured charged oxygen and hydrogen molecules from the ambiance of considered one of Jupiter’s largest moons, Europa. In accordance with a brand new examine co-authored by SwRI scientists and led by Princeton College, these observations present key constraints on the potential oxygenation of its subsurface ocean.
“These findings have direct implications on the potential habitability of Europa,” mentioned Juno Principal Investigator Dr. Scott Bolton of SwRI, a co-author of the examine. “This examine supplies the primary direct in-situ measurement of water elements current in Europa’s ambiance, giving us a slender vary that would assist habitability.”
In 2022, Juno accomplished a flyby of Europa, coming as shut as 352 kilometers to the moon. The SwRI-developed Jovian Auroral Distributions Experiment (JADE) instrument aboard Juno detected vital quantities of charged molecular oxygen and hydrogen misplaced from the ambiance.
“For the primary time, we have been in a position to definitively detect hydrogen and oxygen with in-situ measurements and additional verify that Europa’s ambiance is made primarily of hydrogen and oxygen molecules,” mentioned SwRI Employees Scientist and co-author Dr. Robert Ebert.
The supply of those molecules is regarded as water ice on Europa’s floor. Jupiter’s rampant radiation breaks H2O’s molecular bonds, forsaking oxygen and hydrogen. The heavier oxygen molecules stay extra constrained to the floor, or near-surface ambiance, whereas the lighter-weight hydrogen predominately escapes into the ambiance and past. Oxygen produced within the ice is both misplaced from the ambiance and/or sequestered within the floor. Oxygen retained in Europa’s ice may match its method to its subsurface ocean as a doable supply of metabolic power.
“Europa’s ice shell absorbs radiation, defending the ocean beneath. This absorption additionally produces oxygen inside the ice, so in a method, the ice shell acts as Europa’s lung, offering a possible oxygen supply for the ocean.” mentioned Princeton College Analysis Scholar Dr. Jamey Szalay, the examine’s lead writer. “We put slender constraints on the full oxygen manufacturing at Europa at the moment at round 12 kg per second. Earlier than Juno, earlier estimates ranged from a number of kg per second to over 1,000 kg per second. The findings unambiguously display oxygen is constantly produced within the floor, only a good bit decrease than we anticipated.”
“We designed JADE to measure the charged particles that create Jupiter’s auroras,” mentioned SwRI Employees Scientist and co-author Dr. Frederic Allegrini. “Flybys of Europa weren’t a part of the first Juno mission. JADE was designed to work in a high-radiation atmosphere however not essentially Europa’s atmosphere, which is consistently bombarded with excessive ranges of radiation. Nonetheless, the instrument carried out fantastically.”
The brand new measurements contribute to a higher understanding of Europa and its atmosphere, open the door for newer, extra exact fashions. The examine’s new estimation of how a lot oxygen is produced inside Europa’s floor, for example, might inform future analysis associated to its subsurface ocean and potential habitability. As these observations present the primary charged particle composition measurements inside Europa’s neighborhood, they supply an necessary new window into the moons’ complicated interplay with its atmosphere.
“Europa is a captivating object as a result of scientists are assured a liquid ocean exists in its inside,” Ebert mentioned. “Water is necessary for the existence of life and could be present in or on objects with various traits. Europa is an effective place to seek for water inside our photo voltaic system.”
