Occultation

Same as an Eclipse but is generally applied to total not partial. Eclipses. Planets can OCCULATE each other from a geocentric view. From precise timings by different observers (almost exclusively amateur astronomers), a wide variety of information about celestial objects can be determined, including: planetary atmospheres, coordinates of distant radio sources, dimensions of objects with extended disks, radio and X-ray objects, and the heights of lunar mountains lying near the limb of the Moon.