Geologists find Earth's oldest impact crater in Western Australia

Geologists say they have identified the planet's oldest known impact crater in Western Australia's ancient Pilbara region, a discovery that could significantly reshape the understanding of Earth's formation and the origins of life.

The crater, estimated to be 3.47 billion years old, may have spanned 100 kilometers (62 miles), according to a report by the Australian Broadcasting Corporation on Thursday.

The finding surpasses the previous record holder, the Yarrabubba crater in Western Australia's mid-west, by more than a billion years, said Tim Johnson from Curtin University, co-lead author of the study published in Nature Communications.

"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," Johnson said.

Researchers identified the crater by detecting shatter cones, distinctive rock formations created under the immense pressure of a meteorite impact.

These formations, located about 40 kilometers west of Marble Bar in Pilbara, indicate that a meteorite struck the area at speeds exceeding 36,000 kilometers per hour.

Such an event would have been a major planetary occurrence, leaving behind a crater more than 100 kilometers wide and scattering debris across the globe.

Observations of the Moon suggest that large impacts were common in the early solar system, Johnson noted.

However, he said the absence of truly ancient craters on Earth has led geologists to underestimate their importance.

"This study provides a crucial piece of the puzzle of Earth's impact history and suggests there may be many other ancient craters that could be discovered over time," he said.