Comet Shoemaker–Levy 9 this time a more compact and strong object, probably a small undiscovered asteroid, was the cause. The impact of SL9 highlighted Jupiter's role as a "cosmic vacuum cleaner" (or in deference to the ancients' planetary correspondences to the major organs in the human body, a "cosmic liver") for the inner Solar System (Jupiter Barrier). The planet's strong gravitational influence leads to many small comets and asteroids colliding with the planet, and the rate of cometary impacts on Jupiter is thought to be between 2,000–8,000 times higher than the rate on Earth. The extinction of the dinosaurs at the end of
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