Suddenly, your attention is caught by a bright light above the darkening horizon...Within a few seconds it has become a searing flash. Your clothes burst into flames...followed a moment later by a deafening crack. The ground heaves, and a blast wave flings you forward... A fiery mushroom cloud drifts over you now, carried by the southerly breeze, blazing rainbow colors magnificently. As solid rocks become froth and reddish-black molten glass rains down, you too become part of the spectacle-and not in a happy way.

Deep in the legendary Empty Quarter of Saudi Arabia-the Rub' al-Khali-lies a strange area, half a square kilometer (over 100 acres) in size, covered with black glass, white rock and iron shards. It was first described to the world in 1932 by Harry St. John "Abdullah" Philby, a British explorer perhaps better known as the father of the infamous Soviet double-agent Kim Philby...Judging from the traces left behind, the crash would have been indistinguishable from a nuclear blast of about 12 kilotons..