Evidence indicates that Saturn's icy moon Enceladus is an 'ocean world' that contains all three, making it a prime target in the search for life.
During its 20-year mission, NASA's Cassini spacecraft discovered that ice plumes spew from Enceladus' surface at approximately 800 miles per hour (400 m/s). These plumes provide an excellent opportunity to collect samples and study the composition of Enceladus' oceans and their potential habitability.
Now, researchers from the University of California San Diego have shown unambiguous laboratory evidence that amino acids transported in these ice plumes can survive impact speeds of up to 4.2 km/s, supporting their detection during sampling by spacecraft.
PNAS:
The icy moons of Saturn and Jupiter, Enceladus and Europa, are particularly promising for hosting life, as they have shown evidence for the three important criteria: water, energy, and organic chemicals. Both moons eject their subsurface ocean material as a plume of icy particles, providing the opportunity to study the ocean composition and potential habitability via plume flythrough sampling.
We show that amino acids entrained in ice grains can be detected intact after impact at speeds up to 4.2 km/s and that salt reduces their detectability, validating the predictions from other model systems. Our results provide a benchmark for this orbital sampling method to successfully detect signs of life and for the interpretation of past and future data.
I've always been personally excited by the original Enceladus discovery made by Cassini. It was already such a bizarre little moon to begin with, with the smooth southern geography, but the discovery of these liquid water plumes indicating a warm ocean under the surface was absolutely wonderful. There tends to be excitement and interest in finding aliens far outside of Earth, but if we honest-to-goodness to find alien life or at least the building blocks for it, it'll likely be in the plumes of Enceladus, quite close to home.
