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.
The Cassini-Huygens mission is a cooperative endeavor by NASA, the European Space Agency (ESA), and the Italian Space Agency. The Jet Propulsion Laboratory (JPL), a division of the California Institute of Technology in Pasadena, California, manages the mission for NASA.
On occasion February will have no full moons and January and March will both have two. In this case, you have two calendar blue moons in the same year. However, there can be no more than one in a year's time or it would not be that rare of an event. Using the Farmer's Almanac description there can be a maximum of one in a year.