The crater itself has disappeared but they found the scars of the impact while drilling deep into the planet's crust.
Researchers found the 400-kilometer wide impact zone in the area known as the Warburton Basin, located in central Australia. They believe that it was left by a massive asteroid split into two part before smashing into the ground.
The impact could have caused a massive extinction event, like the one that killed the majority of dinosaurs 66 million years ago, said Dr Andrew Glikson, who heads the team working on a major geothermal project in the area. Glikson added the age of the impact could well exceed 300 million years.
More research is needed to answer at least some of the questions the discovery poses.