In 2005, Cassini . . . endeavored to determine the composition of the exhaust in the most straightforward way possible: by flying through it and registering the thousands of high-speed pellets that collided with its skin. The speed and density of the pellets confirmed that they were ice. Analyzing the precise composition of that ice has taken years, but the results, published this week in the journal Nature, were worth the wait.
Not only is the ice made of ordinary water, but it's salt water, with sodium turning up in the samples no matter how many times the ring material was retested. "Our measurements imply that besides table salt, the grains also contain carbonates like soda," says Frank Postberg, a Cassini scientist working at the Max Planck Institute in Heidelberg, Germany.
Apparently, the chemistry of the ice points to a "large quantity of standing water" on Enceladus, water that "might be unusually hospitable to the emergence of life." (The article explains how liquid water can exist so far from the sun.)
While humanity has given up on the possibility of one day establishing diplomatic relations with little green men on Mars, we still can hope to one day encounter plankton-like organisms on the moons of Saturn.