Potential for Alien Life Found on Saturn Moon Enceladus

Enceladus' plumes may hold evidence of microbial life. (source: NASA)

A new potential source of alien life has been discovered in our solar system, beneath the icy surface of Enceladus, Saturn’s sixth-largest moon. The moon harbors a vast subsurface ocean that erupts through dozens of geysers across the body’s surface. These plumes were detected by the Cassini-Huygens space probe during its 2004-2017 orbit that circled Saturn and its surrounding satellites. A recently published paper that examined Cassini’s Ion and Neutral Mass Spectrometer findings found a diverse chemical composition in Enceladus’ plumes, including compounds that are a prerequisite for the formation of life. Below Enceladus’ icy surface, there very well could be microbial communities of minuscule aliens.

The Cassini–Huygens mission was launched in 1997, arriving at Saturn in 2004, and set about investigating the planet, its rings, and its 146 moons. As part of its mission, the probe deployed the Huygens lander to Titan, the first and only probe to land on a body in the outer solar system. For 13 years, the Cassini probe studied the Saturn system before it exhausted its fuel supply and the probe was flown into the gas giant for destruction. Even six years later, we are still learning new information from Cassini’s data, including the possibility of life on Enceladus.

Thermal imaging of Enceladus' plumes. (source: ESA)

Enceladus’ eruptions are composed mostly of H₂O gas and ice that either falls back to the surface or accumulates into Saturn’s rings along with carbon dioxide, methane, ammonia, and hydrogen. This new research has identified additional compounds by comparing the INMS data to other known mass spectra, identifying hydrogen cyanide, acetylene, propylene, and an unidentified alcohol. Methane and hydrogen suggest the presence of hydrothermal activity which could support microbial life. Hydrogen cyanide has been suggested as a precursor for amino acids, which in turn constitute proteins that comprise proteins. 

Geothermal activity on the ocean surface could harbor microbial communities, drawing their energy source from acetylene, propylene, and the other newly discovered compounds. If so, alien life may be living on Enceladus, but the moon is not the only potential source for such life. The Jupiter Icy Moons Explorer probe, which will arrive in orbit around the gas giant in 2031, is set to investigate Ganymede, Callisto, and Europa’s own subsurface oceans for signs of life. Other contenders include the dwarf planet Ceres and Neptune’s moon Triton. The race is on to discover which of these bodies is the genuine article and harbors alien (albeit microscopic) life.