The Face Behind The Veil. Titan is a little larger than Mercury--the smallest major planet inhabiting our Solar System. Indeed, Titan would have been classified as a major planet in its own right if it orbited our Sun instead of Saturn. The Huygens Probe images lifted the veil from the face of this distant moon-world, revealing a youthful surface that is both smooth and relatively free of impact craters. Huygens also found that this icy, hydrocarbon-saturated moon's climate includes those heavy rains of gasoline, as well as raging, roaring winds. Some of Titan's surface features were found to be hauntingly akin to certain surface features on Earth.
Titan orbits Saturn once every 15 days and 22 hours. Like Earth's large Moon, in addition to many other moons in our Solar System, Titan's rotational period is precisely the same as its orbital period. This means that Titan only shows one face to its parent-planet, while the other face is always turned away.
Since its discovery centuries ago, Ganymede has been the target of a great deal of well-deserved attention from the planetary science community. Earth-bound telescopes have gazed at Ganymede's puzzling, icy surface and, in later decades, flyby space missions and spacecraft, circling around Jupiter, have scrutinized Ganymede--trying to solve its numerous mysteries. These observations ultimately unveiled a complicated, icy moon-world, whose bizarre surface showed a strange and puzzling contrast between its two main types of terrain: the dark, extremely ancient and heavily cratered surface terrain, and the much younger--but still ancient--lighter terrain showing a vast array of mysterious grooves and ridges.