Frozen volatiles including drinking water ice are far more reflective to S-band radio waves than lunar rocks. Radio waves also have diverse features when mirrored off ice than off silicate rock. An Assessment of the signals returned from orbit 234 showed reflection features suggestive of h2o ice for that forever https://andytkymb.educationalimpactblog.com/48583059/5-simple-statements-about-ice-caps-moonrock-explained