A meteorite exploded in the air above Antarctica 430,000 years ago

A micrograph of impact particles from the Sør Rondane Mountains, Antarctica, is shown here.

(CNN)Tiny particles recovered from the summit of a mountain in Antarctica are clues that a meteorite more than 100 yards wide exploded in the sky 430,000 years ago, sending a fireball of vaporized extraterrestrial material to the icy surface, according to new research.

Such "airbursts" are thought to occur more frequently than falling meteors or much larger asteroids that leave craters in the ground -- such as the one that killed off the dinosaurs 66 million years ago. Identifying these space rocks, however, is much harder because they leave few traces in the geological record.
"Asteroids must be sufficiently massive to make it through the atmosphere and reach the ground with enough speed to form an impact crater. Smaller objects, which are much more abundant, explode in the atmosphere and do not form a crater," said Mark Boslough, a researcher at the University of New Mexico, who has studied meteorite explosions but wasn't involved in this latest study.
    Matthias van Ginneken, a research associate from the University of Kent's School of Physical Sciences, collected the 17 dark black particles -- all smaller than 1 millimeter and invisible to the naked eye -- while on an expedition to the Sør Rondane Mountains, Queen Maud Land, in East Antarctica, where the Belgian Princess Elisabeth Antarctica station is based.
      "I first noticed that some of them loo