Saturn’s moon Enceladus has nearly all ingredients for life
Frozen water world checking all the boxes
Scientists have found a potential food source for life on a world in our solar system, raising the tantalizing possibility that organisms could thrive in a place besides Earth.
The researchers emphasize they did not find evidence of life itself. What they did find was hydrogen gas in the geyserlike plumes spurting from the surface of Saturn’s moon Enceladus.
On Earth, hydrogen from seafloor hot springs, also known as hydrothermal vents, is a food stock for microbes and as the base of an elaborate ecosystem.
With the new discovery, nearly every item on the list of supplies essential to life has now been found on Enceladus, including carbon- containing molecules called organic compounds, says Hunter Waite of the Southwestern Research Institute in San Antonio, co- author of a study in this week’s Science about the find.
“Water’s there — check. Organics are in the plume — check. Now we have a chemical source of energy for food — check,” Waite says. Two chemicals essential to living organisms — sulfur and phosphorus — have not been confirmed, but still, “Enceladus is rising to the top of habitable places that exist in the solar system.”
Though Enceladus looks from a distance like a glimmering ball of ice, research has established that the tiny moon has a salty ocean sloshing underneath its frozen shell. Evidence also suggested the water percolates into fissures in the rocky seafloor.
On Earth, seawater that follows a similar path is an important player in marine life. Heated and filled with minerals, the water wafts from the seabed into the open ocean and nourishes bustling ecosystems.
In October 2015, NASA sent its Cassini spacecraft diving through the geysers jetting from Enceladus to measure the plume’s hydrogen level. Researchers then did a “calorie count” of Enceladus’s ocean to determine whether the water holds enough hydrogen and other chemicals to keep living things alive, says study co- author Christopher Glein.
The team concluded that the answer is yes.
NASA plans a mission to Europa in the 2020s, but no new mission to Enceladus is on the books.