Recent advances in digital signal processing have allowed EME contacts, admittedly with low data rate, to take place with powers in the order of 100 Watts and a single Yagi–Uda antenna. [About 8-9 elements according to other sources.]
100W is 50 dBm and the common sensitivity of the receiver is about 0.11 uV (the number for Yaesu FT-991A, SSB @ 2m band) or:
>>> from math import pow, log10 >>> 10*log10(1000*pow((0.11/1000/1000),2)/50) -126.16184634019568
... -126 dB. Assuming that all 50 dBm are radiated straight to the moon (ideal radiation pattern of the antenna):
>>> 50-252 -202
... we are not even close to -126 dB. So what is actual relation between path loss, receiver sensitivity, and also used power and antennas gain?