APOLLO MISSIONS

What remains of the travels of the man on the Moon? Many things, but one thing has gone unnoticed by the general public and yet advanced our knowledge of the Earth-Moon system.

The Apollo 11 astronauts put on the lunar surface (in the Sea of ​​Tranquility), a laser reflector. Since 1969, laser shooting from Earth were used to measure the Earth-Moon distance to a few centimeters. The terrestrial continents drift is measurable and most importantly, the effect of tides on the Moon has been measured showing that the distance from the Moon increases of 3.8 cm per year slowing the Earth rotation (increasing day length of 1.6 millisecond per century).