The Moon is moving away from Earth at a rate of about 3.8 centimeters (1.5 inches) per year.
This happens because of the tidal interaction between the Earth and the Moon.
The Moon's gravity creates tidal bulges in Earth's oceans, which are slightly ahead of the Moon due to Earth's rotation.
These bulges exert a gravitational pull on the Moon that speeds up its orbit, pushing it into a higher orbit farther away from Earth.
This process also slows down Earth's rotation, making our days gradually longer over millions of years.
The distance change is measured precisely by bouncing laser beams off retroreflectors left on the Moon during Apollo missions.
Although the Moon is receding, the effect is very gradual, and it will take millions of years before noticeable changes occur in Earth's tides or day length.