Widely Distributed Debris in Antarctica Points to Airburst Event Long Ago
04.03.2010 - Atmosphere & Space, Ice & Snow, Antarctic
The results of new research presented at the Lunar and Planetary Science Conference (LPSC) in The Woodlands, Texas show that a large rock from space might have exploded over Antarctica thousands of years ago. The object, which probably weighed some 100,000 tons, is thought to have exploded in the Earth’s atmosphere before even reaching the surface in what is known as an airburst. A similar event is the Tunguska event, which flattened a large area of Siberian forest in 1908.
The research is based on a layer of extraterrestrial dust found in Dome C and Dome Fuji ice cores from Antarctica dating back dated about 481,000 years ago. The dust, which was found at two sites some 2,900 km apart; a distribution over such a large area led scientists to conclude that an airburst likely occurred over Antarctica. The researchers also paired the dust found in both ice cores with extraterrestrial debris found in granite from Miller Butte in the Transantarctic Mountains.
The debris found in the mountains contains micrometeorites and small particles known as spherules. These spherules are likely material eroded from a stony meteorite that was heated up while entering the Earth’s atmosphere. They could provide a signature to look for evidence of other airbursts in the geological record.
