Selenodesia
Selenodesia is the science of measuring the earth's moon and its gravitational field .
The term is derived analogously to geodesy ( Greek Selene for moon) and originated around 1967 in the course of the lunar orbiter probes , but is not yet widely used.
Selenodesy, like geodesy, encompasses geometric and dynamic processes, but in contrast to terrestrial surveys , it has to struggle with the problem of greater distances (weaker measurement signals, greater interference) and the reverse side of the moon that is not visible from Earth.
Methods that have so far been very successful are the acquisition of precise orbit data and their analysis to determine the lunar gravitational field . For example, the so-called mascons - strong mass concentrations in the subsurface of the moon - could be detected from the moon orbiters . The fact of the eccentric center of the moon - due to the bound rotation of the moon - was derived from orbital disturbances of lunar satellites.
A kind of triangulation of orbits around the moon also produced good results . The photos of the space probes from the surface of the moon were used to calculate their orbits over the back of the moon in the manner of the reverse section . In addition to the geometric data of the moon, this also confirmed its center of gravity anomaly .