In September 2015, a new study provided an important missing piece to the intriguing puzzle of how our Moon came to be the lovely object that we see today.
Dr. Carolyn Porco, a planetary scientist and leader of the Imaging Science team for Cassini, explained to the press in March 2012 that "More than 90 jets of all sizes near Enceladus's south pole are spraying water vapor, icy particles, and organic compounds all over the place. Cassini has flown several times now through this spray and has tasted it. And we have found that aside from water and organic material, there is salt in the icy particles. The salinity is the same as that of Earth's oceans."
Life as we know it depends on the presence of three ingredients: liquid water; a source of energy for metabolism; and the right chemical ingredients, mainly carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur. With this new discovery of the existence of hydrogen, in the tattle-tale plume shooting out from the surface of Enceladus, Cassini has revealed to the prying eyes of curious astronomers, that this small, icy moon has almost all of these ingredients important for habitability. At this point, Cassini has not detected the presence of phosphorus and sulfur in the hidden subsurface ocean of this distant small world, but many planetary scientists suspect that they will eventually be detected because the rocky core of Enceladus is believed to be similar to certain meteorities that contain these two critical elements.