The Moon is drifting away from Earth at a rate of 3.8 centimeters per year.

The Moon's gradual retreat is caused by tidal friction between Earth's oceans and its crust. As the Moon's gravity pulls on the oceans, it creates a tidal bulge that actually leads the Moon's position. This bulge exerts a gravitational pull on the Moon, accelerating it into a higher and wider orbit.This phenomenon was precisely measured using the Lunar Laser Ranging experiment. Astronauts from the Apollo 11, 14, and 15 missions left retroreflector arrays on the lunar surface. By firing lasers at these mirrors from Earth, scientists at the McDonald Observatory and other facilities have tracked the Moon's distance with millimeter precision since 1969.The current rate of recession is 3.8 centimeters (1.5 inches) per year. This migration has significant long-term consequences for our planet's rotation. To conserve angular momentum, as the Moon moves away and slows down, Earth's rotation also slows by about 2 milliseconds every century.In approximately 600 million years, the Moon will be too distant to create a total solar eclipse. At that point, the Moon's angular size will be consistently smaller than the Sun's. Even when perfectly aligned, the Moon will only produce annular eclipses, often called 'ring of fire' eclipses, leaving the Sun's outer edge visible.