Scientists in Australia have identified what they believe to be the world’s oldest known meteorite impact crater, a finding that could reshape understanding of Earth’s history and the origins of life.
The crater, discovered in the remote North Pole dome region in northwestern Australia, is estimated to be 3.47 billion years old—more than a billion years older than any previously known impact site.
According to the news agency AFP, researchers from Curtin University said their discovery “significantly challenged previous assumptions about our planet’s ancient history.” Professor Tim Johnson, a co-lead of the study, highlighted its importance, stating, “Before our discovery, the oldest impact crater was 2.2 billion years old, so this is by far the oldest known crater ever found on Earth.”
The crater, named the North Pole Crater, was likely formed by a meteorite striking Earth at more than 36,000 kilometres per hour, creating an impact site over 100 kilometres wide. The collision may have sent debris flying across the planet, with molten droplets possibly landing as far away as South Africa, according to ABC News.
The discovery also sheds new light on how meteorites influenced early Earth. Professor Chris Kirkland, another lead researcher, explained that impact craters could have created environments suitable for microbial life. “Uncovering this impact and finding more from the same time period could explain a lot about how life may have got started, as impact craters created environments friendly to microbial life, such as hot water pools,” Kirkland said.
The researchers discovered key geological evidence at the site, including “shatter cones,” distinctive rock formations that form only under extreme pressure from meteorite impacts.
“They’re these beautiful, delicate little structures that look a little bit like an inverted badminton shuttlecock with the top knocked off,” Johnson described. The presence of these formations is considered unambiguous proof of an impact.
The study, published in the scientific journal Nature Communications, also links the discovery to Earth’s crust formation. The tremendous energy from the meteorite strike may have played a role in shaping the planet’s surface. “It radically refines our understanding of crust formation,” Kirkland said, suggesting similar discoveries could further explain how Earth evolved billions of years ago.
However, some scientists remain cautious. According to Australian news outlet ABC, planetary scientist Marc Norman from the Australian National University acknowledged the discovery as “compelling” but noted that more evidence is needed to determine the crater’s exact size and its broader role in Earth’s history.
“While the discovery of this ancient impact crater is interesting, it doesn’t really advance our understanding of how impacts might have influenced how Earth formed and evolved over billions of years,” Norman said.
The researchers plan to conduct further studies in the Pilbara region to search for more ancient craters. “We’ll do the various horrific things we do to rocks … in our labs to analyse them for all sorts of elements and isotopes and microstructures,” Johnson said.
While some past claims of ancient craters, such as those in Greenland, have been inconclusive, the new discovery is backed by strong geological evidence.
