What is the oldest known impact crater on Earth?

The oldest known impact crater on Earth is the Yarrabubba Crater in Western Australia.

Yarrabubba is the eroded remnant of a meteorite impact structure in the Yilgarn Craton. Radiometric dating places the impact at about 2.229 billion years ago, with an uncertainty of roughly 5 million years. The original crater was much larger and more recognizable than the landscape visible today.

The impact happened during the Paleoproterozoic Era, around the time Earth experienced major glaciation. Scientists have modeled how an impact into an ice-covered landscape could have vaporized enormous quantities of water and affected the atmosphere, although its exact climatic consequences remain a research question.

A common mix-up is Vredefort in South Africa. Vredefort is generally described as the oldest large, well-known impact structure and is also the largest confirmed one, but its age—about 2.023 billion years—is younger than Yarrabubba’s. Chicxulub is more famous because it is linked to the extinction of the non-avian dinosaurs, not because it is the oldest.