T. Rex and the Crater of Doom the Brazos river that a tsunami has swept across the Gulf of Mexico millions of years earlier. The discovery was made thanks to a graduate student named Alan Hildebrand that notified Alvarez of the evidence of a crater on the Yucatan peninsula, which had never been published in the scientific literature by the Mexican petroleum geologists that had found it. The age of the crater needed to be determined if it was going to be a candidate for the KT boundary impact, but access to the region was limited by the crater being buried over time and the core samples
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