I noted that the moon drifts away from Earth a few centimeters each year.

However, I'm thinking that the emission of gravitational waves would deter such thing and cause the exact opposite. Furthermore, the orbital decay due to tidal forces should also slow the mon down, which allows the Earth to pull and being the moon closer. What mechanism is working to drag the moon further away from Earth?

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    $\begingroup$ Possible duplicate of Why is the Moon receding from the Earth due to tides? Is this typical for other moons? I think a quick search within this site would have found the answer. You can modify your question in order to ask something different after you read the excellent explanations there. $\endgroup$ – uhoh Mar 15 '19 at 5:07
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    $\begingroup$ Yeah, it's a duplicate. $\endgroup$ – Florin Andrei Mar 15 '19 at 5:11
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    $\begingroup$ This question specifically asks about gravitational waves. Gravitational waves for objects of the masses in question are exceptionally weak, easily overcome by other perturbing effects. Regarding tides, tidal effects make objects orbiting a planet faster than the planet's sidereal day spiral inward. Objects orbiting slower than one orbit per sidereal day (e.g. the Moon) spiral outward. $\endgroup$ – David Hammen Mar 15 '19 at 17:54

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