Saturn’s icy moon Enceladus is one of the most likely spots to harbor alien life in our solar system, and we don’t need to go ashore to find it, according to a study.
Instead, an orbiting space probe would be enough to tell if there is life beneath Encedladus’ icy surface.
Geyser-like ice clouds spurting from the surface of Enceladus offer clues that life may be lurking in the moon’s subterranean ocean.
NASA’s Cassini probe sampled a cloud of material erupting from Enceladus’ surface and found that Enceladus’ thick ice sheet hides a vast, warm saltwater ocean that releases methane, a gas that typically originates from microbial life on Earth.
“We have to look back at Enceladus,” said Régis Ferrière, senior author of the new paper and an associate professor in the UArizona Department of Ecology and Evolutionary Biology.
The new paper is published in the Planetary Science Journal.
Read more:
Ferrière and his collaborators suggest that while the hypothetical total mass of living microbes in Enceladus’ ocean would be small, a visit by an orbiting spacecraft would suffice to ensure that Earth-like microbes do not populate Enceladus’ ocean.
“Obviously, sending a robot that crawls through ice cracks and dives deep to the seafloor isn’t going to be easy,” Ferrière said.
“By simulating data that a more prepared and advanced orbiting spacecraft would only collect from plumes, our team showed that this approach would be sufficient to confidently determine if there is life in Enceladus’ ocean without the need to actually investigate the depths of the moon.”
Located about 800 million miles from Earth, Enceladus completes one orbit around Saturn every 33 hours.
Along the moon’s south pole, at least 100 giant water clouds, resembling lava from a fierce volcano, are gushing from cracks in the icy terrain.
Read more:
Scientists believe that water vapor and ice particles ejected by these geyser-like features contribute to one of Saturn’s iconic rings.
Excess methane detected by Cassini in the smog conjures up images of extraordinary ecosystems found in the lightless depths of Earth’s oceans: hydrothermal vents.
Hot magma beneath the seafloor heats the ocean water in the porous bedrock, creating “white fumes” that spew scorching hot, mineral-saturated seawater.
Organisms without access to sunlight depend on energy stored in chemical compounds released by white smokers for a living.
“The hydrothermal vents on our planet are full of life, large and small, despite the darkness and the insane pressure,” Ferrière said.
“The simplest creatures are microbes called methanogens that power themselves even when there is no sunlight.”
Methanogens convert dihydrogen and carbon dioxide to obtain energy and release methane as a byproduct.
Ferrière’s research group modeled their calculations based on the hypothesis that Enceladus has methanogens living in oceanic hydrothermal vents similar to those found on Earth.
The researchers calculated what the total mass of methanogens would be on Enceladus.
“We were surprised to find that the hypothetical abundance of cells corresponded to the biomass of a single whale in the global ocean of Enceladus,” said Antonin Affholder, postdoctoral research fellow at UArizona.
“The biosphere of Enceladus may be very sparse. Yet our models suggest that it would be efficient enough to feed the plume with enough organic molecules or cells to be picked up by instruments on a future spacecraft.”
“Our research shows that if there is a biosphere in Enceladus’ ocean, signs of its existence can be picked up from plume material without the need to descend or drill, but such a mission would require an orbiter to fly through the smoke multiple times to collect lots of ocean material. “
Watch: Apollo 17 commemorates 50 years of moon landing