Largest moon in solar system reveals an icy world
The largest moon in the solar system has finally claimed a spot on the map after its discovery by Galileo more than 400 years ago.
A team of scientists led by Wes Patterson of the Johns Hopkins Applied Physics Laboratory (APL), Laurel, Md., and Geoffrey Collins of Wheaton College, Norton, Mass., has produced the first global geologic map of Ganymede, a Galilean moon of Jupiter.
Published by the US Geological Survey, the map technically illustrates the varied geologic character of Ganymede's surface, and is the first complete global geologic map of an icy, outer-planet moon.
Patterson, Collins and colleagues used images from NASA's Voyager and Galileo missions to create the map.
It's only the fourth of its kind covering a planetary satellite; similar maps exist for Earth's moon as well as Jupiter's moons Io and Callisto.
Since its discovery in January 1610, Ganymede has been the focus of repeated observation, first by Earth-based telescopes, and later by flyby missions and spacecraft orbiting Jupiter.
These studies depict a complex icy world whose surface is characterized by the striking contrast between its two major terrain types: the dark, very old, highly cratered regions; and the lighter, somewhat younger (but still ancient) regions marked with an extensive array of grooves and ridges.
With a diameter of 3,280 miles (5,262 kilometers), Ganymede is larger than both planet Mercury and dwarf planet Pluto. It's also the only satellite in the solar system known to have its own magnetosphere.
The map details geologic features of the moon that formed and evolved over much of our solar system's history.
(Posted on 13-02-2014)