SUMMARYNew studies suggest Saturn’s moon Enceladus could be a promising place to search for life. Researchers found that microbes like those near Earth’s hydrothermal vents could survive in lab conditions simulating Enceladus’ subsurface ocean, and that plume particles may naturally separate salts, organics, and possible biosignatures into individual ice grains. The findings, published in Science Advances, could help future spacecraft detect signs of life more easily.
New research suggests Enceladus may be an especially promising place to search for extraterrestrial life: microbes similar to those found near Earth's hydrothermal vents survived in lab conditions designed to mimic the Saturnian moon's subsurface ocean. A separate study also found that material blasted from Enceladus' plumes may naturally separate and concentrate salts, organics and potential biosignatures into individual ice grains, potentially making them easier for future spacecraft to detect.
"That is great news in the search for life," Frank Postberg, lead author of one and co-author of the other of these new studies and professor at Freie Universitat Berlin, said in a statement. "Future spacecraft will have to analyze many individual ice particles in the plume. But if they come across one with microbial material in it, they could identify biosignatures in the particle relatively easy with already available technology." Space.com reports: Enceladus isn't the only place in our solar system with water -- so, why is it so exciting in the search for life? Well, it has to do with the seafloor of its extensive, liquid ocean. Down deep at the bottom of this body of water, scientists think hydrothermal processes, or movement or reactions with hot water under the surface, are taking place. The plumes shooting upward from the ocean also contain trace amounts of salts and organic compounds. NASA's Cassini spacecraft found these traces when it flew through the plumes over a decade ago. Between the hydrothermal activity and the organics and minerals in the water, this moon's ocean has a number of aspects that could be involved in supporting life.
What's more, using a combination of Cassini data, theoretical models and laboratory experimentation, in Postberg's new study the team found that the plume's water droplets blasting out into space at up to 621 miles per hour (1,000 kilometers per hour) don't freeze as quickly as expected. Before, scientists thought the freeze would happen instantaneously once the droplets reached space, but Postberg and fellow researchers say they found the freezing would actually happen much slower.
They also found that during this freezing process, the salt, organic compounds (and maybe possible signs of life) in the water droplets separate from one another. Not only that, but the team says that as the particles are blasted out into space, they should often collide with the icy cracks of the planet's surface. This ultimately would leave behind tiny shards of frozen droplets with individually separated out components. Essentially, it's like the planet has organized its oceanic ingredients into tiny, frozen particle fragments. This work is described in two new studies published in the journal Science Advances here and here.