Is the moon moving away from earth?

Answer 1

Yes.

Related Information:

As the result of Earth's spin and it's effect on the tide, the moon gains energy (speed) by stealing Earth's spin energy and uses it to gradually expand its orbit, moving away from the earth.

As the earth spins, the gravity of the moon pulls water, air, and land up towards itself causing a bulge called the tide. Earth's spin then pulls this tidal bulge ahead of the moon. So the tide moves slightly faster than the moon and just east of it. Then the increased gravity effect from the bulge racing ahead of the moon, gradually, almost imperceptibly, pulls the moon forward in its own orbit even faster. This also slows Earth's spin but at a much less perceptible rate.

The end result is a kind of Earth-sponsored sling shot effect. The moon has distanced itself (receded) from Earth in this way, by hundreds of thousands of kilometers, in its long association with Earth.

It is calculated that the current orbit of the moon increases in diameter by about 3.8 cm (about 1 1/2 inches) every year as a result of this effect. Over millions and billions of years this has added up.

The moon is currently moving away from the earth about 3 to 4 times faster than in the past. The spacing of the major oceans and continents allows for a more powerful effect than earlier. But it will not continue this way indefinitely. As the continents continue to drift, affecting the tides, the rate that the moon recedes will also change.

Were the earth to stop spinning, this sling shot effect would stop and the moon's orbit would gradually decay. So, the moon might come crashing down upon the earth someday. Although, that day would certainly be billions of years away.

In fact, current calculations are that the moon would finally stop moving away from earth approximately 15 billion years from now, with collision expected in more than 30 billion years. However, the sun is expected to develop into a red giant and incinerate both the earth and the moon long before then: 6 or 7 billion years from now.