Selenographic coordinates are used to refer to locations on the surface of
Earth's
moon. Any position on the lunar surface can be referenced by specifying two numerical values, which are comparable to the
latitude and
longitude of Earth. The longitude gives the position east or west of the Moon's prime meridian, which is the line passing from the
lunar north pole through the point on the lunar surface directly facing Earth to the
lunar south pole. (See also
Earth's prime meridian.) This can be thought of as the midpoint of the visible Moon as seen from the Earth. The latitude gives the position north or south of the lunar
equator. Both of these coordinates are given in
degrees.