The animation at right, from the University of Arizona, depicts the impact that formed the Chicxulub crater in Yucatan, Mexico. The crater measures 180 kilometers across and the impacting meteorite is estimated to be 10 kilometers wide.
The impact was so great it caused the mass extinction of the dinosaurs.
As big as it is, however, there are other craters even bigger.

Vredefort crater
But the largest crater is known as the Vredefort crater, located in South Africa. It measures 300 kilometers across, and the impact occurred about 2 billion years ago.
Impact craters are still being discovered; the latest may be the 36-46 kilometer wide crater found in the Congo.
This crater was revealed only after deforestation occurred in the area, and if confirmed would be one of the 25 largest impact craters in the world.
The Earth Impact Database has more information on craters around the world.
Meteor Crater, Arizona.



