Is there life on Enceladus?
21 August 2022
Enceladus is one of Saturn’s moons and a strong candidate for the presence of life. Enceladus is special because it has a salty liquid ocean beneath a crust made of hard ice. Often, atmospheric steam plumes are seen spewing ice particles at speeds of up to 800 miles per hour. Enceladus is about 500 km in diameter, just large enough to fit the U.S. state of Arizona. Its atmosphere is composed of hydrogen and carbon dioxide and trace amounts of methane detected by Cassini. Microbes called methanogenic archaea are known to produce methane as a waste product. This microorganism may explain why methane is present in the atmosphere of Enceladus.
To test this hypothesis, Simon Rittmann and his team at the University of Vienna, Austria, exposed these microbes to conditions that mimic the atmosphere of Enceladus. The team was exposed to conditions that mimicked the atmosphere of Enceladus, which is inferred from Cassini.
Gases present in the atmosphere of Enceladus were fed to the microorganisms in quantities consistent with Cassini’s findings. These gases include hydrogen and carbon dioxide, which the microbes use to assemble the energy they require. On the canopy of that, the coercion and temperatures found in the Enceladus ocean were also reproduced. Temperatures ranged from 0 to 90 degrees Celsius and pressured up to 50 Earth atmospheres. Microorganisms can thrive in such extreme conditions, and Chris McKay of NASA’s Ames Research Center believes, ‘This (research) team has taken the first step in showing experimentally that methanogens can live under the conditions expected on Enceladus.
Computer simulations were performed to calculate the amount of hydrogen produced by the decomposition of olivine minerals. Olivine is a material found in the solid core of the Moon. The results showed that enough hydrogen is produced to allow microorganisms to survive. Furthermore, the seafloor, in contact with rocks and minerals, is considered the best environment for microorganisms to grow. It is also estimated that the temperature in this area is slightly higher than 0°C, and the atmospheric pressure is about 50 bar.