NASA Rethinks The ‘Habitable Zone’ While Looking For Life On Europa, Enceladus and Titan
Since we’ve been able to look up to our own solar system, we’ve always wondered if there was any life besides us. Earth sits in what scientists like to call the ‘Habitable Zone.’ It’s also been called the ‘Goldilock Zone” since the position of the planet in the solar system is just right for life. To put it more directly, the habitable zone is is the range of orbits around a star within which a planetary surface can support liquid water given sufficient atmospheric pressure.
With that being said, panelist’s at SXSW this year pointed to the existence of vast oceans of liquid water on two of Saturn’s moons and one of Jupiter’s when asked if we shared life in our solar system with other forms of life.
Recent scientific findings have led to new excitement over possible life in the oceans of Europa (one of Jupiter’s 67 moons), or in that of the moon Enceladus or Titan, which both hang out around Saturn.
“When we think about the solar system, we’re used to a very traditional picture where we have eight planets,” says Cynthia Phillips, Europa Staff Scientist at NASA’s Jet Propulsion Laboratory (JPL). “For a long time, people have been interested in a thing called the habitable zone, where water can be a liquid on the surface. Only recently have we started to expand our notion of a habitable zone to include the outer planets.”
On Europa: “All the factors necessary for life,” Phillips insists. “Under an ice crust estimated to be 19 to 25 kilometers thick, Europa has an ocean that contains more liquid water than all the oceans on Earth combined. The moon also has abundant carbon, phosphorous, and nitrogen,” she continues. “There may also be hydrothermal vents or a “radiation environment” at the surface “that creates molecular species that trickle down into the ocean, helping to support life. Finally, there has been plenty of time for life to arise and evolve: Europa’s “ocean has been liquid throughout the age of the solar system,” which is about 4.57 billion years, Phillips says.
As with usual scientific interest this big, NASA plans on launching a mission called the Europa Clipper in the middle of the next decade. The surface is Europa will be high with radiation, so the probe will only pick up samples during a flyby.
“Many types of life need that gradient to live,” she explains. “Sulfate-reducing and sulfate-oxidizing bacteria help move electrons from reduced places to oxidized places, and, in doing so, get energy.”
All of this new thinking about microbial life on moons within our reach has scientists with different backgrounds of research coming together. “Geologists are talking to chemists, who are talking to biologists, oceanographers, and people who study hydrothermal vents. A lot of us are starting to attend the same meetings, and talk more, so a lot of the information that was previously isolated in one field is now being disseminated among all of planetary science. These communities have really started coming together.” says Morgan Cable, an astrochemist at NASA’s JPL.
J. Hunter Waite published a paper last year about hydrothermal vents on Enceladus. It details on how the Cassini mission detected hydrogen plumes emitted from the moon.
“There was so much hydrogen that the only logical explanation is hydrothermal activity,” through a geochemical process called serpentinization, Cable explains
Cassini, in 2015, also picked up something called nanograins, which are little spheres of silica.
“The only way you can get these is if you have liquid water in contact with the crust of the seafloor at 90 degrees C or above.” Cable clarified.
Out of the three moons, it appears Titan could be the strangest of them all. Titan is coated with organic material that covers the ice, and sits upon a water ocean. The below video really explains the details of the potential life going on within these moons.
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Jeff Sorensen is an author, writer and occasional comedian living in Detroit, Michigan. You can look for more of his work on The Huffington Post, UPROXX, BGR, ScreenRant, and by just looking up his name.