A mile-wide impact crater found in the Antarctic ice sheet may have been created by a meteorite, perhaps the size of a house, smashing into the Earth in 2004.
Scientists on an aerial research flight over East Antarctica spotted the ring-like structure on what should be flat ice. The structure appeared to be several broken icebergs that were surrounded by a 1.24-mile wide circle, further surrounded by a few smaller circles in the ice.
There were previous reports of an infrasound caused by an exploding meteorite detected in Sept. 2, 2004, with six detectors picking up the infrasound. Scientists placed the source of the infrasound in East Antarctica.
A separate report from Davis Station, a permanent base of Australia off the East Antarctica coast, narrated a dust trail thrown up into the atmosphere during that time, suggesting that an object landed on the ice shelf.
Analysis suggested that a meteorite the size of a house broke up while in the Earth's atmosphere above Antarctica, then its remains crashed into the ice. It now seems that the impact site has been found.
Geophysicist Christian Müller from the Fielax surveying company was the first to spot the crater, located on the King Baudoin Ice Shelf, on a flight on Dec. 24.
Müller said that he saw the unusual structures on the ice surface while on a routine measuring flight, and that he immediately thought that the structures could be an impact crater created by a meteorite.
The researchers from Germany's Alfred Wegener Institute were studying the rock located underneath the ice. The aircraft that they were on was equipped with a radar that can penetrate the ice to determine the geology underneath.
The team returned to the site on Dec. 26 to take pictures and video, and used lasers to develop a topographical map of the location. The team also used radar to develop an image of what is beneath the circular structure on the ice shelf.
While the details are still being processed, geophysicist Graeme Eagles, the leader of the geophysical survey team of the Alfred Wegener Institute at the Princess Elisabeth Antarctic Research Station, said that there seems to be a disturbance in the snow and ice on the top of the ice shelf, supporting the theory that a meteorite crash formed the crater.
Eagles said that nothing has been fully confirmed, only that there is something unusual with the structure found at the King Baudoin Ice Shelf.
Studies by Australian scientists estimated that the meteorite weighed between 600 tons and 1,900 tons, and was traveling as fast as 29,080 miles per hour before exploding with a force equivalent to 12,000 tons of TNT.
