Signs of Life in the Darker Reaches of Space

The most recent astrological celestial body found to be capable of hosting complex life is not Mars, instead it is a moon approximately 1,201,300,000 kilometers away from the red planet.

The moon is named Enceladus, and is the sixth largest moon to orbit the second largest planet in our solar system, Saturn.

Enceladus is covered in an external sheet of ice which envelops a large subsurface ocean, and its south polar region witnesses large, cryovolcanular plumes emitted through the satellite’s icy sheet.

The Cassini spacecraft was responsible for the recent discoveries, using two mass spectrometers to perform, “compositional in situ measurements of material emerging from the subsurface of Enceladus. These measurements were made inside both the plume and Saturn’s E ring, which is formed by ice grains escaping Enceladus’ gravity.” (1).

Typically, only compounds with molecular masses of around 50 atomic mass units, or amu, have been found in the plume of celestial bodies; however, the plume emerging from Enceladus was found to contain more complex organic compounds with masses of 200 amu.

These much larger compounds act as presets for the creation of a sustainable environment and indicate that the ocean below the moon’s ice crust is capable of hosting complex life.

The compounds found include macromolecules made up of long carbon chains, and molecular hydrogen, which, “‘provides a source of chemical energy supporting microbes that live in the Earth’s oceans near hydrothermal vents,’ Hunter Waite, an atmospheric scientist and principal investigator of the study,” said in a statement from the Southwest Research Institute in San Antonio, Texas (2).

Thus, researchers and scientists more heavily consider the possibility that some of the complex molecules like the molecular hydrogen found in the analysis of Enceladus’ plume may be sourced from hydrothermal vents on the bottom of the sea floor, much like those found here on Earth.

If these vents do exist on the moon, they also may, in a similar fashion to their earthly counterparts, act as formidable micro ecosystems providing sustenance and a suitable habitat for complex microorganisms and primitive life forms to thrive in. Scientists also hypothesize that the heavy organic compounds found outside of the moon’s surface may only be fragments of even larger compounds broken through collision with the rapidly moving dust-analyzing mechanism attached to Cassini, further expanding the possibility for life on the distant moon.

So far, Enceladus is the only extraterrestrial body recorded to host organic systems and processes capable of synthesizing complex organic compounds, and scientists are now actively working to uncover more information on the satellite, excited by the prospect of possible alien life.

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1. Postberg, Frank, et al. “Macromolecular Organic Compounds from the Depths of Enceladus.” Nature News, Nature Publishing Group, 27 June 2018, www.nature.com/articles/s41586-018-0246-4.
2. Hickok, Kimberly. “No Aliens, But Scientists Find More Evidence for Life on a Saturn Moon.” LiveScience, Purch, 2 July 2018, www.livescience.com/62969-potential-life-molecules-on-enceladus.html.
3. “SwRI Scientists Find Evidence of Complex Organic Molecules from Enceladus.” Southwest Research Institute, 27 June 2018, www.swri.org/press-release/evidence-complex-organic-molecules-enceladus.
4. Cover image found on European Space Agency