Scientists from Australia’s National University have uncovered what they believe to be the world’s largest asteroid impact zone in central Australia. This, according to Clarissa Thorpe on the Australian Broadcast Network news site. The pictures or rock formations above are from that ABC Net News article.
According to article, Dr. Andrew Glikson and his team discovered two impacts each about 120 miles wide, which combined would be the largest impact known on Earth. Dr. Gilkson believes that the two impacts were caused by an asteroid that split in two before impact. According to the article, the actual craters have disappeared, but the impacts were verified by geothermal research drilling. Check out the link above to the article for more.
Someone wrote a novel about an asteroid or bolide striking the earth.