A meteorite slammed into Earth about 3 billion years ago, creating what researchers now say is the planet’s oldest known impact crater, according to a new study.
The crater, known as the North Pole Dome impact structure, is located in the Pilbara region of Western Australia, home to some of Earth’s oldest rocks. The revised age makes the crater roughly 800 million years older than the next-oldest confirmed impact structure, the Yarrabubba crater, also in Western Australia. Researchers published the findings on June 23 in the journal Geology.
The study helps resolve a long-running debate over the age of the ancient crater. While scientists had previously identified the North Pole Dome as an impact site, its exact age remained uncertain.
Minerals preserved evidence of the impact
Chris Kirkland, a professor in the School of Earth and Planetary Sciences at Curtin University and lead author of the study, said the impact left behind minerals that preserved evidence of when the collision occurred.
To determine the crater’s age, researchers analyzed minerals within shatter cones, rare rock formations created by powerful shock waves during a meteorite impact.
Earth's oldest known impact crater may have formed about 3 billion years ago, according to a new study.
Researchers dated minerals inside Western Australia's North Pole Dome impact structure and found evidence that it is the only recognized meteorite crater from the Archean Eon. pic.twitter.com/dnLcC2T9Lt
— Tom Marvolo Riddle (@tom_riddle2025) June 24, 2026
The team examined zircon, apatite, calcite, and muscovite from two shatter-cone-bearing rock samples, along with a shocked quartz vein formed by hot fluids moving through fractured rocks after the impact. Among those minerals, zircon provided the strongest evidence.
Zircon crystals can survive for billions of years and preserve records of ancient geological events. Researchers found unusual branching and skeletal-like zircon crystals that appear to have been altered by the extreme heat generated during the impact. By dating those crystals and comparing the results with other minerals, the team concluded that the crater formed slightly more than 3 billion years ago.
New findings address earlier disagreements
The findings differ from a study published last year by Kirkland and colleagues that suggested the impact occurred 3.47 billion years ago. That estimate was based on evidence from shatter cones, which form when shock waves travel through rock during a meteorite impact.
A separate study published months later in Science Advances challenged that conclusion, arguing that the impact could be no older than 2.7 billion years.
The new study places the impact between those two estimates and offers additional evidence to support the revised age.
Matching mineral ages strengthens the case
Researchers said the age recorded in zircon closely matched the age preserved in apatite, providing independent evidence for the timing of the collision.
The team also suggested that younger ages reported in previous research may reflect later tectonic and thermal events rather than the impact itself. Heat, pressure, and geological activity over billions of years may have altered some of the rocks and reset their mineral ages.
A rare window into the Archean Earth
Kirkland said dating ancient impact craters remains difficult because billions of years of heat, pressure, and fluid activity can erase or modify evidence of the original event.
Despite those challenges, researchers believe the new dating results provide the clearest estimate yet for when the impact occurred.
The revised age gives North Pole Dome a unique place in Earth’s history. Researchers say it is the only recognized impact crater from the Archean Eon, a period between about 4 billion and 2.5 billion years ago when the planet’s earliest continents were taking shape.
The finding offers a rare opportunity to study a major meteorite impact from one of the least understood chapters of Earth’s geological history.
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