This important measurement was made using Cassini's INMS instrument, which detects gases with the goal of determining their composition. INMS was designed to sample the upper atmosphere of Saturn's large, smoggy moon Titan. However, after Cassini's surprising discovery of a tall plume if icy spray erupting from cracks on Enceladus in 2005, planetary scientists turned its detectors to that small moon.
A moon is a natural body that is in orbit around a planet, and it is kept in place by both the host planet's gravity and the gravity of the moon itself. Some planets possess orbiting moons; some do not. There are several theories explaining how Earth's Moon came to be. At this point, the favored model is termed the giant impact theory, often playfully called the Big Whack or Big Splash theory by astronomers when they are in a humorous frame of mind. These funny nicknames were derived from the central tenet of the theory, which is that a Mars-sized body, named Theia, smacked into the primordial Earth billions of years ago. The collision caused part of our planet's crust to be hurled violently into space. Some of this shattered, somersaulting debris was snared into Earth-orbit, where it formed a host of moonlets that were ultimately pulled together by gravity to evolve into our Moon.
I'm not anti-science, in fact I think our world has only improved because of it. But science should be no less immune from a serious reality check than was the church in the dark ages. I believe in the bible , and I'm sure it gives us only a very short time to the second coming of Christ. But even at that I would never put the bible against science. I am satisfied that science is the book of how, and the bible is the book of why.