Scientist have found a massive impact crater in Australia, formed by a giant meteorite that presumably struck the Earth millions of years ago.
A team of geophysicists from the Australian National University (ANU) said on Monday they found signs of a 250-mile (400-kilometer)-wide impact zone, from a huge meteorite, deep inside the Earth’s crust in the Warburton Basin – an area near the borders of South Australia, Queensland and the Northern Territory
The researchers discovered the largest impact zone ever found on Earth by drilling over a mile deep into the earth as part of a geothermal research as a surface crater from the impact has long disappeared.
An impact event, which is a collision between astronomical objects, can have significant physical and biospheric consequences.
Major impact events, such as extraterrestrial impact or internal geological change, have significantly shaped Earth’s history by causing periods of extreme environmental shifts over a time span of 4.5 billion years.
“Large impacts like these may have had a far more significant role in the Earth’s evolution than previously thought,” said the lead researcher, Andrew Glikson from the ANU’s Planetary Science Institute.
According to the findings published in the journal Tectonophysics, the massive asteroid had broken in two halves before hitting the Earth 300 to 600 million years ago, causing the fracture of the crust by intense heat and pressure at depths of more than 12 miles (19 kilometers).
“The two asteroids must each have been over 10 kilometers across -- it would have been curtains for many life species on the planet at the time,” Glikson said.
The exact date of the impact crater remains unspecified, Gilkson said. “It’s a mystery -- we can’t find an extinction event that matches these collisions. I have a suspicion the impact could be older than 300 million years.”
Despite having changed the planet’s temperature, the meteorite has not been determined to be as destructive as the one, which led to extinction of dinosaurs and other species 66 million years ago,
Scientists still need to connect the meteorite strike to a particular period of extinction on the planet.