ABSTRACT
The answer is ''by radar". Clementine carried highly sophisticated radar equipment, and one lunar scientist, Stewart No7ette, proposed to direct radar beams right into the craters. Tlle pulses of energy bounced back for analysis might, he claimed, show whether or not ice existed. Three years earlier the same sort of experiment had been carried out with the planet Mercury, not from a probe, of course, but with the giant radio "dish" at Arecibo in Puerto Rico. This has been built in a natural hollow in the grmmd and is 1000 feet (305 m) in diameter. Arecibo scientists had found that permanently darkened polar craters on Mercury reflected radio pulses just as ice might be expected to do, and though many people were highly sceptical the investigation was certainly worth following up. If ice existed on Mercury, then why should it not exist on the Moon too?
