NASA announced on Thursday that its Cassini spacecraft mission to Saturn has gathered new evidence that there's a chemical reaction taking place under the moon's icy surface that could provide conditions for life.
A moon circling around Jupiter and another around Saturn could be the closest places in our system where NASA thinks the highest concentration of "ingredients for life" exist.
In 2015, researchers said that there was evidence of a warm ocean under the moon's surface, as NPR's Geoff Brumfiel reported.
Because, Dr. Spilker says, "we now know that Enceladus has nearly all the ingredients you would need to support life as we know it".
The hydrogen was detected during a 2015 flyby when NASA's Cassini spacecraft raced through plumes of vapor spewing from cracks at the moon's south pole, scientists said. Either way the implications are profound.
The Cassini probe - a joint project of NASA, the European Space Agency and Italy's ASI space agency - will now undergo a course correction to enable it to study Saturn's rings before being plunged into the gas giant's atmosphere in September, ending its 13-year mission to explore the distant planet and its 62 known moons. By flying through a plume spraying out of its icy shell, Cassini was able to detect molecular hydrogen.
The new research suggests that Saturn's this moon has a chemical energy source capable of supporting life. The primary ingredients required to sustain life include liquid water; a source of energy for metabolism; and the right chemical ingredients, primarily carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur.
This photo of Saturn's moon Enceladus, taken by the Cassini spacecraft, shows the cracks in the icy surface.
"Some of the most primitive metabolic pathways utilized by microbes in these environments involve the reduction of carbon dioxide (CO2) with H2 to form methane (CH4) by a process known as methanogenesis", Jeffrey Seewald wrote in an accompanying piece in the same Science magazine. Details of the discovery were published in the journal Science today. Cassini also looked into the plume composition during its flybys. The Hubble space telescope is observing Europa from a distance for evidence of plumes of water, similar to the ones seen on Enceladus. In laymen's terms, Enceladus could have hydrothermal vents that are similar to those found on Earth.
The plumes have led scientists to infer that hydrothermal chemical reactions between the moon's rocky core and its ocean - located under the ice crust - are likely occurring on Enceladus.
Enceladus, a moon of Saturn, may harbor life analogous to that which exists near the hydrothermal vents in Earth's oceans. Water, ice, traces of methane, salts and other carbon compounds were found as well as silicates and hydrogen, according to a report from The Guardian.
Neither the Europa mission nor Cassini - the spacecraft that has been exploring Saturn and its moons for more than a decade - are created to detect life itself. Scientists do not have as much close up data about Europa as they do for Enceladus, however, and the Hubble data are not definitive.
Hubble Space Telescope images of possible plumes on Jupiter's moon Europa. Then the Galileo mission reached Europa in 1996 and revealed for the first time that there was an ocean on another planet.