The moon bounces around all over the place--it never hits the same apogee or perigee twice. What you see published are only averages, and maxima and minima figures derive from computer simulations that can predict (ahead and backward) about 5ky. In spite of this chaos LLR (lunar laser ranging) purports to measure the rate at which the moon is receding due to tidal drag--this must require considerable averaging and modeling over many years.
The point being, it's a lot easier to simulate lunar attraction on satellites than to measure the rate of lunar recession. --AGF
