The moon moves 3.8 cm away from Earth every year

 

The average distance between the Moon and Earth is about 238,855 miles (384,400 kilometers). However, this distance can vary depending on the Moon's position in its elliptical orbit around the Earth. At its closest point (perigee), the Moon can be about 225,623 miles (363,104 kilometers) away from Earth, while at its farthest point (apogee), it can be about 251,000 miles (405,500 kilometers) away.

Moon's Orbit Expanding 

 The Moon is slowly moving away from Earth at a rate of about 3.8 centimeters (1.5 inches) per year. This may not seem like a lot, but over millions of years, it can have a significant impact on the Earth's rotation and tides. This movement is due to the tidal forces between the Earth and Moon, which cause the Moon's orbit to gradually expand. However, the rate of the Moon's movement away from Earth is not constant and can vary slightly over time due to a number of factors, such as changes in the Earth's rotation and fluctuations in the Moon's orbit.

Tidal forces between the Earth and Moon

Tidal forces between the Earth and Moon are the gravitational forces that cause the ocean tides and other effects, such as the Moon's gradual movement away from the Earth. These tidal forces arise because the gravitational attraction between the Earth and the Moon is not uniform across the planet. The gravitational pull is stronger on the side of the Earth facing the Moon than on the opposite side, which causes a distortion of the planet.

This distortion leads to a high tide on the side of the Earth facing the Moon and another high tide on the opposite side, with low tides in between. As the Earth rotates, the high tides and low tides move around the planet, resulting in the familiar pattern of two high tides and two low tides every day.

The same tidal forces that cause the ocean tides also exert a drag on the Moon's orbit, which gradually causes it to move away from the Earth at a rate of about 3.8 centimeters (1.5 inches) per year. This is because the Earth's rotation is gradually slowing down due to the transfer of energy from the Earth's rotation to the Moon's orbit. This process, known as tidal acceleration, leads to the gradual expansion of the Moon's orbit and the lengthening of the day on Earth.