A new study conducted by NASA's Jet Propulsion Laboratory in Pasadena, California suggests that the ocean condition under the icy surface of Jupiter's moon Europa has the necessary balance of energy for life to exist, even with the absence volcanic hydrothermal activity.
For the study, researchers from NASA JPL compared the potential of the Jovian moon to produce oxygen and hydrogen with that of Earth, through processes that do not directly involved volcanism. The researchers found out that the oxygen production of both Europa and Earth exceed hydrogen production by almost 10 times, suggesting that the rocky exterior of Europa may be much more complex and more earthlike than what researchers have previously thought.
"We're studying an alien ocean using methods developed to understand the movement of energy and nutrients in Earth's own systems. 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," said Steve Vance, a planetary scientist at JPL and lead author of the study, in a statement.
In order to further understand the cycling of life's major elements in the ocean of Europa, researchers calculated how much hydrogen that could potentially be produced in Europa's ocean as seawater reacts with rock, in a process called serpentinization. They also measured the amount of oxidants produced in Europa.
According to the study, hydrogen are released during the serpentinization process when the water percolates into spaces between mineral grains and reacts with the rock to form new minerals, while oxidants are made when water ice molecules were split apart by Jupiter's radiation.
"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, a planetary scientist at JPL and co-author of the study, said in a press release.
The discovery of the earthlike balance of balance in the production of oxygen and hydrogen in Europa does not necessary mean that life can occur in the Jovian moon. Lots of research are still needed to further understand how ocean's in Europa works.
By 2020, NASA plans to send a highly capable radiation-tolerant spacecraft into a long, looping orbit around Jupiter to perform repeated close flybys of Europa, taking high-resolution images, determining the composition of the moon's icy surface and faint atmosphere and investigating the moon's ice shell, ocean and interior.