ANCIENT WIPEOUT Preliminary evidence indicates that a low-altitude meteor explosion around 3,700 years ago destroyed cities, villages and farmland north of the Dead Sea (shown in the background above) rendering the region uninhabitable for 600 to 700 years. Archaeologists at a site in what's now Jordan have found evidence of a cosmic calamity A superheated blast from the skies obliterated cities and farming settlements north of the Dead Sea around 3,700 years ago, preliminary findings suggest. Radiocarbon dating and unearthed minerals that instantly crystallized at high temperatures indicate that a massive airburst caused by a meteor that exploded in the atmosphere instantaneously destroyed civilization in a 25-kilometer-wide circular plain called Middle Ghor, said archaeologist Phillip Silvia. The event also pushed a bubbling brine of Dead Sea salts over once-fertile farm land, Silvia and his colleagues suspect. People did not return to the region for 600 to 700 years, said Silvia, of