Coordinate System
A crater named Anat provides the reference point for measuring longitude on Ganymede. By definition, Anat is at 128 degrees longitude.
Read more about this topic: Ganymede (moon)
Famous quotes containing the word system:
“... in America ... children are instructed in the virtues of the system they live under, as though history had achieved a happy ending in American civics.”
—Mary McCarthy (1912–1989)