The Chicxulub crater is more than 180 km ( 110 mi ) in diameter , making it the third largest confirmed impact crater . The bolide which formed the crater was at least 10 km ( 6 mi ) in diameter . The crater is more than 180 km ( 110 mi ) in diameter , making the feature one of the largest confirmed impact structures on Earth ; the impacting bolide that formed the crater was at least 10 km ( 6 mi ) in diameter .