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:
“Ethics and religion differ herein; that the one is the system of human duties commencing from man; the other, from God. Religion includes the personality of God; Ethics does not.”
—Ralph Waldo Emerson (18031882)