Melbourne: Researchers have recently found world's largest 400 km wide asteroid impact zone in central Australia.
The crater from the impact millions of years ago has long disappeared. But a team of geophysicists has found the twin scars of the impacts, the largest impact zone ever found on Earth, hidden deep in the earth's crust.
Lead researcher Dr Andrew Glikson from the ANU School of Archaeology and Anthropology said the impact zone was discovered during drilling as part of geothermal research, in an area near the borders of South Australia, Queensland and the Northern Territory.
Dr Glikson said that the two asteroids must have been over 10 kilometres across, it would have been curtains for many life species on the planet at the time.
The exact date of the impacts remains unclear. The surrounding rocks are 300 to 600 million years old, but evidence of the type left by other meteorite strikes was lacking.
The two impact zones total more than 400 kilometres across, in the Warburton Basin in Central Australia. They extend through the Earth's crust, which was about 30 kilometres thick in this area.
The research is published in journal Tectonophysics.