Europa's ocean may have the "necessary balance of chemical energy for life", according to new research by Nasa.
A study modelling ocean conditions on the Jovian moon suggests that even though it "may lack volcanic hydrothermal activity", the water could be capable of supporting life. Whether or not the ocean exists has been subject to debate, though evidence suggests the presence of a salty ocean beneath Europa's icy shell.
Analysis of the ocean was inspired by "methods developed to understand the Earth's own systems", the team explained. "We're studying an alien ocean using methods developed to understand the movement of energy and nutrients in Earth's own systems," said Steve Vance, who lead the study. "The cycling of oxygen and hydrogen in Europa's ocean will be a major driver for Europa's ocean chemistry and any life there, just as it is on Earth."
The study compared the moon's "potential" for producing hydrogen and oxygen to that of Earth by calculating how much hydrogen could "potentially be released as seawater reacts with rock" – a process called 'serpentinisation'.
The team found that "the amounts of hydrogen would be comparable in scale" to that of Earth – meaning that oxygen production is about ten times higher than hydrogen production. "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," said Kevin Hand, co-author of the study.
The results also suggest that, like neighbouring moon Io, there may be volcanic activity on Europa.
The team now hope to examine and understand other elements – carbon, nitrogen, phosphorus and sulphur –on the moon's ocean. Nasa is "currently formulating a mission to explore Europa and investigate whether the icy moon might be habitable".
In 2020, the space agency hopes to send a "capable, radiation-tolerant spacecraft" into orbit around Jupiter to take high-res images of Europa to investigate its icy shell. Nine solar-powered vessels will investigate the moon in a mission that will comprise of nearly 50 flybys.
This article was originally published by WIRED UK
