Johnson reports the crater can be seen today only in a 35-mile wide dome that marks exactly where the asteroid impacted.

The discovery of a 3.47-billion-year-old crater in WA's Pilbara region pushes back the age of the earliest-known impact site on Earth by more than one billion years.

The formation is rare in the geologic world and ranks as one of the world's finest examples of columnar basalt. Its columns ...