# Expanding Moon's orbit and newtonian mechanics

the 2 body problem of earth and moon is suppose to be perfectly described by Newtonian mechanics / Kepler's laws.

How ever the moon's orbit is been moving away from earth in contradiction to the orbit described by Newtonian mechanics.

So are we to conclude that even Newtonian mechanics does not perfectly describe the solution to 2 body problem?

Specifically the reason the moon is getting further away is because of tidal friction - angular momentum is being taken from the Earth's rotation and imparted to the moon's orbit. There is obviously an upper limit to how much this continue (namely, the limit of $L_{\rm moon} + L_{\rm earth}$ with respect to their center of mass).