Chicxulub crater Chicxulub crater The Chicxulub crater (; ) is an impact crater buried underneath the Yucatán Peninsula in Mexico. Its center is located near the town of Chicxulub, after which the crater is named. It was formed by a large asteroid or comet about in diameter, the Chicxulub impactor, striking the Earth. The date of the impact coincides precisely with the Cretaceous–Paleogene boundary (K–Pg boundary), slightly less than 66 million years ago, and a widely accepted theory is that worldwide climate disruption from the event was the cause of the Cretaceous–Paleogene extinction event, a mass extinction in which 75% of plant
Ammonius (crater) by the IAU in 1976. Before it was called Ammonius, the crater was planned to be called Lyot proposed by Hugh Percy Wilkins and Patrick Moore, instead, Lyot would be named in the Moon's southeastern limb. Ammonius (crater) Ammonius is a bowl-shaped lunar impact crater with a slightly raised rim and is named after It is located on the floor of the walled plain Ptolemaeus, about 30 kilometers northeast of the crater midpoint. Just to the north on the lava-flooded floor of Ptolemaeus is a relatively prominent "ghost" crater: the discernible buried rim of a pre-existing crater. The diameter of