Bangkok, Thailand, 11 June 2006: A massive crater in Antarctica discovered by scientists using NASA satellite data may have been caused by a meteor that wiped out more than 90 percent of the species on Earth 250 million years ago, a geologist said. The 300-mile-wide crater was found in the Wilkes Land region of the East Antarctic Ice Sheet. When the scientists overlaid their gravity image with airborne radar images of the ground beneath the ice, they discovered imprints of lumps and ridges from the meteor that indicated impact.
‘‘This is a strong candidate for the cause of the extinction,’’ Ohio State University geologist Ralph von Frese said. The prevailing theory holds that the Permian-Triassic extinction was caused by a series of volcanic eruptions over thousands of years that buried what is now Siberia in molten rock and released tons of toxic gases into the atmosphere, changing the Earth’s climate.