With its striated surface and impressive pillars, the bright young moon of Saturn’s planet Enceladus is a dynamic place to search for life.
Scientists believe that Enceladus, like Europa, is also a glacial world with a global ocean under its crust. But Europa’s gravity keeps the moon’s plumes closer to the surface, while Enceladus’ plumes rise into massive plumes that constantly generate a field of ice particles around the moon and even contribute to one of Saturn’s rings.
The Cassini spacecraft spotted Saturn in 2005, spied plumes of icy water and gas erupting at 800 miles per hour (1,287.5 kilometers per hour) through warm cracks in the ice crust, called “tiger stripes.”
The discovery of molecular hydrogen in one of Enceladus’ plumes was a highlight of Cassini’s closest mission to the moon in 2015. Molecular hydrogen forms as a result of the interaction between water and rocks when in a hydrothermal environment, scientists believe.
Previous discovery of complex organic molecules in the plumes suggested that the Moon might 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 a byproduct of the reactions that produce amino acids. In Earth’s oceans, vents on the ocean floor create ideal conditions for these reactions to occur. The researchers believe that this same process might unfold in Enceldaus.
Measurements of methane, molecular hydrogen and carbon dioxide in the global oceans show that this body of water has the chemical energy needed for microbes to produce methane — if there are microbes.