Geologists have discovered the world’s oldest known impact crater, located in the heart of the ancient Pilbara region of Western Australia.
Analysis of rock layers in the region suggests that the crater, at least 100 kilometers wide, was created when a large space rock slammed into Earth about 3.47 billion years ago.
Our planet was almost completely covered in water at the time.
The discovery pushes back the record for the oldest impact crater on Earth by more than a billion years. The previous record holder, the Jarrabuba impact structure, is also located in Western Australia.
“Given how rare such evidence is due to Earth’s geological recycling processes, this is a major advance in understanding the early Earth,” Chris Kirkland of Curtin University in Australia, who led the research, told Space.com.
Researchers estimate that the space rock that created the crater was traveling at 22,000 miles per hour, and the impact scattered debris across the planet.
But despite its global impact, the event wasn’t just a destructive force, Kirkland says.
The crater that formed may have played a key role in fueling early life.
The high pressures created by shock waves released after a meteorite impact are known to alter minerals within rocks, sometimes turning them into clear glass.
This, in principle, allows more sunlight to penetrate the cracks that break the rocks, creating the physical and chemical conditions necessary for early life to thrive.
Kirkland explains that meteorite impacts lead to the formation of hot, mineral-rich pools of water that could have served as a breeding ground for early microbial life, the precursor to life as we know it.
