A Moon of Saturn May Be More Habitable Than Expected

Prior to its dramatic and intentional crash into Saturn in 2017, the Cassini spacecraft gathered data that suggests Enceladus, one of Saturn’s moons, contains most of the ingredients that are essential to life on Earth. Ammonia, carbon, nitrogen and oxygen were all found to be present on Enceladus, and research from last year revealed that the moon also harbors methane, another potential sign of life.

Now, new research using computer modeling and data from Cassini has found that Enceladus might contain phosphorus, a building block of life as we know it. While the scientists did not find the element directly, their analysis suggests that Enceladus’ ocean could host about as much phosphorus as Earth’s seawater does—or even more, according to a press release.

“We found evidence that one of the key elements that’s needed for life on Earth should be present in high abundance in the ocean of Enceladus,” Christopher Glein, a co-author of the new paper and a senior scientist at the Southwest Research Institute, tells Mashable’s Mark Kaufman.

The findings were published in September in the Proceedings of the National Academy of Sciences.

Enceladus is a much smaller moon than our own, with a diameter less than one twenty-fifth that of Earth. Beneath its surface, which is covered by water ice, lies a global ocean. In what appear to be continuous geysers, Enceladus shoots streams of icy water particles into space at 800 miles per hour, according to NASA.

Until now, scientists were skeptical that Enceladus could host much phosphorous at all. After all, phosphorous on Earth is produced through weathering of rocks on land, and Enceladus, being a moon of ice and ocean, doesn’t have any land, Space.com’s Keith Cooper reports. While past research has pointed to a scarcity of phosphorus on Enceladus, the new study used more detailed computer simulations to reach its conclusion, according to Mashable.

The researchers modeled how phosphorus-rich minerals might dissolve into the ocean from Enceladus’ core, writes Space.com. While the scientists haven’t collected any material from the core, Cassini proved that it’s rocky, and meteorites and other space rocks provide a sense of what its composition could be like, per Mashable.

“We don’t know exactly what the rocky core of Enceladus is made of, but we can make good guesses based on what we find in other places in the solar system,” Geoff Collins, a planetary scientist at Wheaton College who was not involved with the study, tells Mashable.

Their simulations revealed that a core of that predicted composition, by interacting with the moon’s ocean water, would make Enceladus relatively rich in phosphorus, according to the paper.

Phosphorus helps form the basis of life as we know it. It works with sugars to bond nucleotide bases to DNA's double helix, per Space.com. It also plays a key role in the creation of cell membranes and in the formation of human bones and teeth. When given to plants and put in livestock’s food, it increases agricultural yields, Vera Thoss, a chemist at Bangor University in Wales, wrote in The Conversation in 2017.

The finding that Enceladus may have significant amounts of its phosphorus in its ocean “shows Enceladus is more habitable than previously thought,” Glein tells Mashable.

Will Sullivan | | READ MORE

Will Sullivan is a science writer based in Washington, D.C. His work has appeared in Inside Science and NOVA Next.