The Yarrabubba impact structure in remote Western Australia is the oldest known asteroid crater on Earth, according to a study published yesterday (January 21) in Nature Communications.
At 2.229 billion years old, the Yarrabubba crater is older than both the Vredefort Dome in South Africa (2.023 billion years old) and Canada’s Sudbury Basin (1.850 billion years old), report the authors in the study. These are the only other precisely dated Precambrian impact structures that are currently known. Yarrabubba’s estimate has a margin of error of just 5 million years.
Originally stretching roughly 70 km wide, the Yarrabubba resisted reliable estimates of its age because of erosion and plate tectonics. It is now an elliptical structure with a diameter of approximately 20 km. Geochronologist Timmons Erickson of the NASA Johnson Space Center and his colleagues sought to assign the crater an exact age by studying concentrations of uranium, thorium, and lead ...
