Huge circle in Antarctic ice hints at meteorite impact [1]

During a routine flight over the Antarctic ice shelf on 20 December last year, geophysicist Christian Müller [2] spotted something strange: a huge, 2-kilometre-wide circle on the ice.

Müller, a contractor with research consultants Fielax from Bremerhaven, Germany, was in Antarctica as part of a polar survey conducted by the German Alfred Wegener Institute [3]. Six days after spotting the weird ice-ring, he and his colleagues returned and flew over the site at two different altitudes, to photograph and scan it. Their working theory is that the ring marks an ice crater left by a large meteorite that slammed into Antarctica in 2004.