Since it began orbiting Saturn in 2004, NASA's Cassini spacecraft and its hitchhiker, the European Space Agency's Huygens probe, have yielded reams of data of the planet and its satellites. Now in the last year of its second mission, called Equinox, the spacecraft is flying by Saturn's moons. Two of them, Titan and Enceladus, have become the darlings of researchers thanks to the presence of organic chemicals, water ice and, possibly, subterranean oceans of liquid water.
Water ice is one of the building blocks of Saturn's moons. It accounts for 70 to 90 percent of their composition, according to Bonnie Buratti, a senior research scientist at NASA's Jet Propulsion Laboratory at the California Institute of Technology. Water ice is strewn among the rocky debris in the planet's rings, and throughout the outer solar system in general. With the possibility of a liquid ocean buried on Enceladus the moon may have the three things necessary for life as we know it: heat, liquid water and food.
While ancient oceans on Mars may have once supported life, the search now is likely work for fossil hunters. On the other hand, "Enceladus is more like a laboratory for the origin of life," Buratti says. The elements are probably there, but alien life itself remains speculation. Here are the latest images and findings from the strange, stunning moons of Saturn.