Chicxulub impactor Chicxulub impactor The Chicxulub impactor ( ), also known as the K/Pg impactor and (more speculatively) as the Chicxulub asteroid, was an asteroid or other celestial body some in diameter which struck the Earth at the end of the Cretaceous period, approximately 66 million years ago, creating the Chicxulub crater. It impacted a few miles from the present-day town of Chicxulub in Mexico, after which the impactor and its crater are named. Because the estimated date of the object's impact and the Cretaceous–Paleogene boundary (K–Pg boundary) coincide, there is a scientific consensus that its impact was the Cretaceous–Paleogene extinction event
Stefan (crater) a small ray system, which is indicative of a relatively young impact. The interior floor of Stefan is a generally level surface that is marked by several impacts. The most notable is a ring-shaped crater rim projecting up through the southern half of the floor. Near the midpoint is a low hill, possibly the buried remnant of a central peak. Stefan lies at the approximate margin of the Coulomb-Sarton Basin, a 530 km wide impact crater of Pre-Nectarian age. By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that