By Peter Weiss
Now and then, ultra-high-energy cosmic rays from space slam Earth’s atmosphere with energies too huge to be explained. Scientists suspect they may have exotic origins, such as yet-to-be-discovered relics of the Big Bang. They rank among the major puzzles of astrophysics (SN: 8/15/98, p. 101).
Only a handful of such rays has been detected, but researchers hope to soon observe greater numbers of them with a supergiant detector–the moon. Building on theories from the 1960s, scientists suspect that ultra-high-energy particles striking the moon may interact with lunar soil to produce detectable bursts of microwaves. A new experiment simulating that burst-generating effect in a giant sandbox suggests that a moon-based detector might just work.