About 200 million years ago, a large meteorite came hurtling through the darkness of outer space heading for a direct impact with planet Earth at the confluence of what would later become known as Houston, Stewart and Montgomery Counties in the state of Tennessee. The meteorite was nearly 300 metres in diameter, weighed more than 100 million tons and was travelling in excess of 58,000 km per hour when it impacted with the Earth exploding with the force of a 1,000 megaton bomb. The resulting impact crater was 600 metres deep and nearly 12 kilometres across. Read more (830kb, PDF)