A team of Australian scientists has uncovered evidence of one of the largest and oldest asteroid strikes known to have ever hit Earth.

A team of Australian scientists has uncovered evidence of one of the largest and oldest asteroid strikes known to have ever hit Earth. 
The object is believed to have been around 12 to 18 miles wide with a resulting crater several times that magnitude, though the exact impact location is still unknown. 
A press release issued recently by the Australian National University quotes one of the paper’s authors, Dr. Andrew Glikson, as saying, “Any craters from this time on Earth's surface have been obliterated by volc