Saturn’s moon Enceladus could support species similar to Earth

Saturn’s moon Enceladus has phosphorous. The finding came from recently analyzed icy particles emitted from the natural satellite’s ocean plumes, detected by NASA’s Cassini spacecraft. The discovery means Enceladus has all the chemical building blocks for life as we know it on Earth. “This is the final one saying, ‘Yes, Enceladus does have all of the ingredients that typical Earth life would need to live and that the ocean there is habitable for life as we know it,” Morgan Cable, astrobiology chemist at NASA’s Jet Propulsion Laboratory, told The Wall Street Journal.

Cassini, which plunged to its demise in Saturn’s atmosphere in 2017, collected data by passing through Enceladus’ continually erupting geysers at its south pole and Saturn’s E ring, also containing escaped particles from the moon. Beneath its icy crust, Enceladus has a warm subsurface ocean, over 30 miles deep, enveloping the entire moon. The eruptions at its south pole spit icy particles into space, allowing research crafts like Cassini to study the ocean’s chemical makeup without taking a dip or even touching the moon’s surface.

Data from previous missions indicated the moon had all of life’s essential building blocks — carbon, hydrogen, nitrogen, oxygen and sulfur — except for phosphorous. A team of planetary scientists found nine grains containing phosphate (phosphorous bound to oxygen atoms) among around 1,000 samples initially overlooked by researchers. The tiny amount detected reflects phosphorous’ scarcity. “Of the six bioessential elements, phosphorus is by far the rarest in the cosmos,” said Frank Postberg, the study’s lead author.

Of course, Enceladus containing the requirements for life doesn’t necessarily mean life exists on the moon. “The next step is to figure out if indeed it is inhabited, and it is going to take a future mission to answer that question,” Cable said. “But this is exciting, because it makes Enceladus an even more compelling destination to go and do that kind of search.” NASA will get a chance to learn more when the Dragonfly mission heads for Saturn’s moon Titan in 2027; another proposed mission could arrive at Enceladus around 2050. In addition, the James Webb Space Telescope may help further to illuminate the chemical breakdown of Enceladus’ warm subterranean ocean.