Gases In Enceladus’ Subsurface Ocean Possibly Provide Conditions Favorable To Life

Eddie Gonzales Jr. – MessageToEagle.com – New study from planetary scientists at the University of Washington, suggests that the subsurface ocean of Saturn’s moon Enceladus probably has higher concentrations of carbon dioxide and hydrogen and a more Earthlike pH level, than previously thought.

Thus, the gases possibly provide conditions favorable to life.

This illustration shows NASA’s Cassini spacecraft diving through the plume of Saturn’s moon Enceladus, in 2015. New research from the University of Washington, to be presented at the coming AbSciCon2019 conference, indicates that the moon’s subsurface ocean probably has higher than previously known concentrations of carbon dioxide and hydrogen and a more Earthlike pH level, possibly providing conditions favorable to life. NASA

“The presence of such high concentrations could provide fuel — a sort of chemical “free lunch” — for living microbes, or, it could mean “that there is hardly anyone around to eat it,” lead researcher Lucas Fifer a UW doctoral student in Earth and space sciences, said in a press release.

Enceladus is a small moon, an ocean world about 310 miles (500 kilometers) across. Its salty subsurface ocean is of interest because of the similarity in pH, salinity and temperature to Earth’s oceans. Plumes of water vapor and ice particles — spotted and studied by the Cassini spacecraft — erupt hundreds of miles into space from the ocean through cracks in Enceladus’s ice-encased surface.

The plumes aren’t chemically the same as the ocean from which they erupt at 800 miles an hour; the eruption process itself changes their composition, according to Fifer and colleagues (ESS faculty members David Catling and Jonathan Toner).

Fifer and colleagues say the plumes provide an “imperfect window” to the composition of Enceladus’s global subsurface ocean and that the plume composition and ocean composition could be much different.

The team used data from the Cassini mission and  a computer simulation to get a clearer idea of the composition of Enceladus’s inner ocean’s. They found “significant differences” between Enceladus’s plume and ocean chemistry.

“It’s better to find high gas concentrations than none at all,” said Fifer. “It seems unlikely that life would evolve to consume this chemical free lunch if the gases were not abundant in the ocean.”

Those high levels of carbon dioxide also imply a lower and more Earthlike pH level in the ocean of Enceladus than previous studies have shown. This bodes well for possible life, too, Fifer said.

“Although there are exceptions, most life on Earth functions best living in or consuming water with near-neutral pH, so similar conditions on Enceladus could be encouraging,” he said. “And they make it much easier to compare this strange ocean world to an environment that is more familiar.”

There could be high concentrations of ammonium as well, which is also a potential fuel for life. And though the high concentrations of gases might indicate a lack of living organisms to consume it all, that does not necessarily mean Enceladus is devoid of life. Microbes just aren’t abundant enough to consume all the available chemical energy.

The gas concentrations can be used to determine an upper limit for certain types of possible life that could exist in the icy ocean of Enceladus.

In other words, he said: “Given that there’s so much free lunch available, what’s the greatest amount that life could be eating to still leave behind the amount we see? How much life would that support?”

Thanks to Cassini and its data, researchers can obtain yet more knowledge about this ocean and everything in it, and future spacecraft missions will offer even more, according to Filer.

Written by Eddie Gonzales Jr. – MessageToEagle.com Staff