The oldest impact crater on Earth
A three-billion-year-old scar in the Pilbara is the only Archean crater we have found.
- When
- Known to
- ± 30 million years
- Era
- Mesoarchean, Archean
Shatter cones and shocked zircon at the North Pole Dome in Western Australia record an asteroid strike, dated by impact-recrystallised zircon to 3,024 ± 7 million years. Its age has been fiercely argued — an initial 3.47 Ga estimate was challenged with a case for younger than 2.77 Ga — but the crystal ages support around 3.0. Earth must have been struck constantly; erosion and subduction have erased everything else this old.