With its striped surface and impressive plumes, Saturn’s tiny bright moon Enceladus is a dynamic place to search for life.
Like Europa, Enceladus is also an icy world with a global ocean beneath its crust, scientists believe. But Europa’s gravity keeps its plumes closer to the surface, while Enceladus’ plumes rise up in massive columns that continuously generate a field of ice particles around the moon and even contribute to one of Saturn’s rings.
Observing Saturn in 2005, the Cassini spacecraft spied plumes of icy water and gas blasting up at 800 miles per hour (1,287.5 kilometers per hour) through warm cracks in the ice crust, called “tiger stripes.”
The detection of molecular hydrogen in one of Enceladus’ plumes was a highlight of Cassini’s closest flyby of the moon in 2015. The molecular hydrogen forms as a result of the interaction between water and rocks when it’s in a hydrothermal environment, scientists believe.
Previous detection of complex organic molecules in the plumes has further suggested that the moon could support life as we know it. Enceladus likely has hydrothermal vents that expel hot mineral-rich water into the subsurface ocean.
Amino acids are the building blocks of life. Organic compounds are the byproduct of the reactions that create amino acids. In Earth’s oceans, vents on the ocean floor create ideal conditions for these reactions to occur. Researchers think this same process could be unfolding on Enceldaus.
Measurements of methane, molecular hydrogen and carbon dioxide in the global ocean show that this body of water has the chemical energy necessary for microbes to produce methane — if there are microbes.
