World’s Oldest Asteroid Crater Found in Australia
World’s Oldest Asteroid Crater Found in Australia
Researchers have confirmed the Yarrabubba crater in Australia as the oldest asteroid crater on Earth, dating back 2.229 billion years. This oldest asteroid impact site, hidden beneath layers of eroded rock, provides new insights into how ancient asteroid collisions shaped Earth’s climate and geology.
Yarrabubba, located near Meekatharra, approximately 600 kilometers (approximately 372 miles) northeast of Perth, is now recognized as at least 200 million years older than the Vredefort crater in South Africa, which was previously considered the oldest.
The impact site spans 70 kilometers (43.5 miles) wide and has been worn down over billions of years, making its identification a breakthrough.
A team of geologists from Curtin University in Australia and Imperial College London determined its age by analyzing zircon and monazite minerals in rock samples.
These minerals contain uranium, which naturally decays into lead over time. By measuring this decay, researchers calculated that the asteroid struck 2.229 billion years ago. Their findings were published in Nature Communications.
Link to ancient climate change
One of the most significant aspects of the discovery is its timing. The impact aligns closely with the end of the Huronian Glaciation, a period when much of Earth was covered in ice. Scientists believe this may not be a coincidence.
A research team led by Thomas Davison at Imperial College London conducted computer simulations to evaluate the impact’s effects on Earth’s climate. The models indicated that if a 7-kilometer-wide (4.3 miles) asteroid collided with an icy surface at a speed of 17 kilometers per second (10 miles per second), it could vaporize significant amounts of ice, subsequently releasing over 200 billion tons of water vapor into the atmosphere.
Crater Wednesday. The Yarrabubba Crater in Western Australia. Is the oldest known impact crater on earth dating back 2.29 billion years ago. pic.twitter.com/UpDIUySHeZ
— Mr. William Henry Leonard Poe
(@WadeJo8) February 19, 2025
Water vapor is a powerful greenhouse gas, capable of trapping heat. Some experts suggest this sudden release may have contributed to warming the planet, potentially playing a role in ending the global ice age.
“We see a remarkable coincidence between the age of Yarrabubba and the termination of a global glaciation,” said Nicholas Timms, a geologist at Curtin University. “If this impact released enough water vapor, it might have tipped the climate toward warming.”
Why Yarrabubba was so hard to find
Unlike the Chicxulub crater in Mexico, which still has clear geological markers from the asteroid impact that wiped out the dinosaurs 66 million years ago, Yarrabubba is nearly invisible. Wind, water, and shifting tectonic plates have eroded its surface over billions of years.
The breakthrough in identifying the site came when researchers detected arc-shaped magnetic anomalies beneath the ground—patterns characteristic of buried impact structures. Rock samples from deep within the area also showed signs of extreme shock pressure, confirming an asteroid impact.
The end of an ice age
The discovery of Yarrabubba has raised new questions about the role of asteroid impacts in shaping Earth’s climate. If a collision could have contributed to ending an ice age, could future impacts trigger significant climate changes?
“This discovery reminds us that asteroid impacts are not just catastrophic events,” said Chris Kirkland, lead researcher at Curtin University. “They are also powerful forces of planetary change.”
Though Yarrabubba no longer has a visible crater, its impact on Earth’s history remains. As the oldest known asteroid strike, it will continue to influence scientific discussions on the past and future of the planet.