NASA's new findings: Signs of life may be near the surface of Enceladus and Europa

Europa, a moon of Jupiter, and Enceladus, a moon of Saturn, are believed to have subsurface oceans beneath their icy crusts that may harbour life. Recent NASA experiments indicate that if these oceans do support life, organic molecules like amino acids and nucleic acids might survive just below the ice surface despite intense radiation. This means that robotic landers exploring these moons might not need to dig very deep to detect these molecules.

Alexander Pavlov of NASA’s Goddard Space Flight Center notes that, for Europa, amino acids could be found up to eight inches (around 20 centimetres) below the surface in areas less impacted by meteorites. On Enceladus, amino acids may survive even closer to the surface, less than a tenth of an inch (a few millimetres) from it.

While the harsh surface conditions of these moons, marked by high radiation from their host planets and cosmic events, render them uninhabitable, their subsurface oceans, warmed by tidal forces, could potentially support life if they contain necessary elements and compounds.

Sampling Depth Insights

Lead author Alexander Pavlov from NASA’s Goddard Space Flight Center notes that for Europa, a sampling depth of about eight inches (20 centimetres) in relatively undisturbed areas could be sufficient to detect amino acids. In contrast, on Enceladus, these molecules could survive within just a few millimetres of the surface. The harsh surface conditions of these moons, characterised by high radiation from their planets' magnetic fields and cosmic events, make their icy exteriors inhospitable, but their subsurface oceans, heated by tidal forces, remain promising habitats for life.

Radiolysis Experiments

The research team conducted experiments to understand how amino acids might survive under these moons' conditions. By simulating Europa and Enceladus environments, they found that amino acids degrade more quickly when mixed with dust but are more stable when associated with microorganisms. This suggests that biological material might offer some protection against radiation, potentially preserving life-signalling molecules longer.

Future Missions and Life Detection

These findings are crucial for designing future missions to Europa and Enceladus. Understanding where and how to sample is essential, as areas with less silica-rich dust might offer better chances for detecting preserved organic molecules. This research enhances our ability to search for life beyond Earth, providing valuable insights into where to look for signs of life in our solar system and beyond.




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