January 9, 2012 To Preserve History on the Moon, Visitors Are Asked to Tread Lightly By KENNETH CHANG California’s catalog of historic artifacts includes two pairs of boots, an American flag, empty food bags, a pair of tongs and more than a hundred other items left behind at a place called Tranquillity Base. The history registry for New Mexico lists the same items. That might be surprising, since Tranquillity Base is not in New Mexico or California but a quarter of a million miles away, in the spot where Neil A. Armstrong and Buzz Aldrin stepped onto the moon in 1969. But for archaeologists and historians worried that the next generation of people…