The Moon’s first satellite

On 3 April 1966, the Soviet Union scored another Moon first when Luna 10 entered lunar orbit. Not only was it the first spacecraft to do this, it was the first to orbit any astronomical body other than Earth. The advantage of an orbiter over the earlier flybys and impactors is that it can make close-range scientific observations over a much longer period. Luna 10’s batteries lasted 56 days in orbit, during which it sent back valuable data on the Moon’s composition, gravity field and lack of atmosphere or magnetic field.