After a long and dangerous journey through the space between planets, the Cassini/Huygens Spacecraft reached Saturn on July 1, 2004. On December 25, 2004, the Huygens Probe was purposely liberated from the Cassini Orbiter. Huygens then began its historic descent through the dense blanket of golden-orange fog to at last lift the veil hiding Titan's long-hidden face.
Galilean Moons Of Jupiter. One dark, clear January night in 1610, Galileo Galilei climbed to the roof of his house in Padua. He looked up at the sky that was speckled with the flickering fires of a multitude of starry objects, and then aimed his small, primitive "spyglass"--which was really one of the first telescopes--up at that star-blasted sky above his home. Over the course of several such starlit, clear winter nights, Galileo discovered the four large Galilean moons that circle around the largest planet in our Sun's family, the enormous, gaseous world, Jupiter. This intriguing quartet of moons--Io, Europa, Ganymede, and Callisto--were named for four of the numerous mythic lovers of the King of the Roman gods.
Ganymede, and four other moons dwelling in our Sun's family, possess liquid water beneath their frigid crusts of ice. The others are Saturn's moons, Titan and Enceladus, and two other Galilean moons of Jupiter--Europa and Callisto. Planetary scientists think the oceans of Europa and Enceladus are in contact with rock--thus making these two moons high-priority targets for future astrobiology missions.