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:
“He is not a true man of science who does not bring some sympathy to his studies, and expect to learn something by behavior as well as by application. It is childish to rest in the discovery of mere coincidences, or of partial and extraneous laws. The study of geometry is a petty and idle exercise of the mind, if it is applied to no larger system than the starry one.”
—Henry David Thoreau (1817–1862)