3 billion-year crater Western Australia is oldest on Earth

Scientists have dated an asteroid impact crater in Western Australia to approximately three billion years old, making it the oldest known such structure on Earth. The finding, based on direct mineral analysis, resolves a debate over the age of the North Pole Dome formation in the Pilbara region.

Researchers from Curtin University used advanced dating techniques on minerals within rocks that show signs of the ancient impact. The key evidence came from the mineral zircon, which exhibited unusual, skeletal shapes interpreted as being modified by the intense heat of an asteroid strike. A second mineral, apatite, which formed as hot fluids moved through the shock-damaged rocks, was dated independently and returned the same result of around three billion years.

Lead researcher Chris Kirkland said the agreement between the two mineral systems gives confidence that they are seeing the signature of a single major impact event. The new age establishes the North Pole Dome as the only recognized impact crater from the Archean eon, a period when Earth's earliest continents were forming.

The finding revises an earlier hypothesis from the same research team. In 2025, they had proposed the...