The asteroid that hit Vredefort located in the Free State Province of South Africa is one of the largest to ever impact Earth, estimated at over 10 km (6 miles) wide, although it is believed by many that the original size of the impact structure could have been 250 km in diameter, or possibly larger(though the Wilkes Land crater in Antarctica, if confirmed to have been the result of an impact event, is even larger at 500 kilometers across). The town of Vredefort is situated in the crater. Dating back 2,023 million years, it is the oldest astrobleme found on earth so far, with a radius of 190km, it is also the most deeply eroded. Vredefort Dome bears witness to the world’s greatest known single energy release event, which caused devastating global change, including, according to many scientists, major evolutionary changes. Tomorrow I'll be posting an impact-crater map of the planet (it's scary!). Original posting by Casey Kazan.
See also Deep Impact -A Video