Saturn's icy moon Enceladus may be able to support organisms that are similar to those that thrive in the harshest environments and conditions on Earth.
Liquid Ocean Beneath Enceladus Icy Shell
Enceladus has frigid temperatures at the surface, but there is liquid ocean beneath the moon's icy shell. The water is believed to reach up to 194 degrees Fahrenheit at the bottom.
Earlier studies also showed that the floor of this ocean likely features hot water vents that are similar to those that host ecosystem on Earth's ocean floors.
Now, the new research published in the journal Nature Communications on Feb. 27 showed proof that microbes can potentially survive in the ocean's water.
Study researcher Ruth-Sophie Taubner, from the University of Vienna, and colleagues conducted an experiment on three species of unicellular organisms. These organisms thrive near the hydrothermal vents on our planet, where they are beyond the reach of sunlight and are sustained by chemical nutrients.
Methane-Producing Organism Grew Well In Enceladus-Like Conditions
The researchers found that the methanogen Methanothermococcus okinawensis is most suited for studies that would simulate under Enceladus-like conditions. Methanogens are microbes that produce methane as a metabolic byproduct.
Taubner and colleagues exposed M. okinawensis to an environment similar to the hydrothermal vents on Enceladus' seafloor. They found that the microbes grew well and produced methane.
Methane In Plumes Of Enceladus
Before the Cassini spacecraft crashed last year, it found traces of methane in the plumes of Enceladus.
An alien life that shares the same characteristics as M. okinawensis may possibly explain the presence of methane on Saturn's satellite. Researchers said that the methane that Cassini detected may have been produced by methanogens.
"We were able to show that, under putative Enceladus conditions, biological methane production occurs in the lab," said study Simon Rittmann, from the University of Vienna in Austria. "Hence, some of the methane detected on Enceladus could in principle be of biological origin,"
The researchers also modeled the water-rock formation that likely occur in the moon's interior and found that these reactions produce lots of molecular hydrogen that can sustain methanogenic organisms such as M. okinawensis if these organisms exist on Enceladus.
"Methanogenic archaea are among the organisms that could potentially thrive under the predicted conditions on Enceladus," the researchers wrote in their study.
"Here we show that a methanogenic archaeon, Methanothermococcus okinawensis, can produce CH4 under physicochemical conditions extrapolated for Enceladus."
