Luna 10

Luna 10 (E-6S series) was a 1966 Soviet Luna program, robotic spacecraft mission, also called Lunik 10. It was the first artificial satellite of the Moon.

The spacecraft

Scientific instruments included a gamma-ray spectrometer for energies between 0.3—3 MeV (50–500 pJ), a triaxial magnetometer, a meteorite detector, instruments for solar-plasma studies, and devices for measuring infrared emissions from the Moon and radiation conditions of the lunar environment. Gravitational studies were also conducted.
Luna 10 conducted extensive research in lunar orbit, gathering important data on the strength of the Moon’s magnetic field, its radiation belts, and the nature of lunar rocks (which were found to be comparable to terrestrial basalt rocks), cosmic radiation, and micrometeoroid density. Perhaps its most important finding was the first evidence of mass concentrations (called “mascons”)—areas of high density below the mare basins that distort lunar orbital trajectories. Their discovery has usually been credited to the American Lunar Orbiter series.