Geologists have discovered the world's oldest known impact crater; it sits in the heart of Western Australia's ancient Pilbara region.

An analysis of rock layers in the region suggests a crater at least 62 miles (100 kilometers) wide was carved after a large space rock struck Earth roughly 3.47 billion years ago, when our planet was almost completely covered in water. The discovery pushes back the record for the oldest impact crater on Earth by more than 1 billion years — the previous record holder, the Yarrabubba impact structure, also is in Western Australia.