NASA/JPL-Caltech
Scientists just found the primary ingredients for life bursting from an ocean on Saturn's moon Enceladus.
A new analysis by NASA data reveals the presence of organic compounds in the plumes of liquid water which shoot into space from the ocean below Enceladus's icy crust.
Those compounds, that carry nitrogen and oxygen, play a key role in producing amino acids - complex molecules which serve as the building blocks of proteins. Without proteins, life on Earth could not exist.
Scientists have suspected that the ocean below Enceladus's surface could harbor the ingredients for life. Researchers detected other organic molecules coming from the icy moon before, but that's the first time anybody has detected them dissolved in the water.
This means the compounds could undergo deep-sea chemical reactions that produce amino acids.
These findings were published in the journal Monthly Notices of the Royal Astronomical Society.
On Enceladus, jets of ocean water and ice frequently shoot out into space through warm cracks in the moon's crust.
The scientists analyzed data on the chemical composition of those plumes, and found new organic compounds, some of which containing nitrogen and some containing oxygen.
Those compounds were dissolved in the ocean water below Enceladus's surface. Then they evaporated with the surface water, condensed, and froze into the moon's icy crust. The plumes blew the compounds into space, where NASA's Cassini spacecraft sensed them as it flew nearby.
According to Science Alert, the compounds are another sign that Enceladus may have its version of a process that creates life on Earth
Deep in the planet's oceans, seawater mixes with magma which bubbles up through cracks in the ocean floor. This interaction produces smoky hydrothermal vents which can get as hot as 370 degrees Celsius (700 degrees Fahrenheit).
The vents spew hydrogen-rich hot water, fuelling chemical reactions that transform organic compounds into amino acids. Those amino acids can then stack onto one another like Legos to form proteins, which are crucial for replicating the genetic information that creates life.
The process allows life to develop without the assistance of sunlight. The importance of that is explained by Enceladus's ice surface is highly reflective and sends what little sunlight the moon receives back into space. Any life there would need to develop in the dark.
In 2018, the team discovered similar organic molecules from the same data. However, the molecules weren't water-soluble; the researchers believe they sat on the surface of the Enceladus ocean.
Such compounds would need to dissolve into ocean water to interact with hydrothermal vents and produce life. Until now, scientists were unsure if organic compounds on Enceladus did that.
The data scientists used to arrive at both of those findings came from NASA's Cassini mission. This probe launched in 1997 and spent 13 years exploring Saturn and its moons.
Back in September 2017, the mission ended when scientists intentionally sent the spacecraft plummeting into Saturn. They did that to avoid contaminating Enceladus or Titan, another nearby moon which could also harbor life, with Earthly microbes.
Cassini found that Enceladus conceals a global ocean of liquid saltwater below its surface, and captured jets of that water shooting into space. The probe flew through these plumes and collected data about their composition in 2008.
Scientists plan to continue studying this and other data collected by Cassini for decades to come.
Moreover, NASA intends to send a probe to Saturn's moon Titan, that's another a prime target in the search for alien life due to its abundant organic compounds. The mission is set to launch a nuclear-powered helicopter named Dragonfly toward Titan in 2026.
The spacecraft is estimated to arrive at Titan in 2034, then begin hunting for signs of life.
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