Chicxulub crater is the larger Shiva crater, though the structure's status as an impact crater is contested. The collision of Comet Shoemaker–Levy 9 with Jupiter in 1994 demonstrated that gravitational interactions can fragment a comet, giving rise to many impacts over a period of a few days if the comet should collide with a planet. Comets undergo gravitational interactions with the gas giants, and similar disruptions and collisions are very likely to have occurred in the past. This scenario may have occurred on Earth at the end of the Cretaceous, though Shiva and the Chicxulub craters might have been formed 300,000 years
Thomas Bopp Planetarium at the university. In 1997, as comet Hale–Bopp reached its brightest point, Bopp's brother and sister-in-law were killed in a car accident after photographing the comet. "This has been the best week of my life. And the worst," Bopp told a "National Geographic" reporter. Bopp and his father Frank have had an asteroid named after them, , discovered October 5, 1991, by Carolyn and Gene Shoemaker. In 1997 Gene Shoemaker and his wife, both famous for co-discovering comet Shoemaker–Levy 9, were involved in a fatal car crash while observing Hale-Bopp. Gene died in the crash and his ashes were