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
Comet ISON Central Bureau for Astronomical Telegrams identified the object as an asteroid, and it was listed on the Near Earth Objects Confirmation Page. Follow-up observations by independent teams were the first to report cometary features. Therefore, under the International Astronomical Union's comet-naming guidelines, Comet ISON was named after the team that discovered it, rather than the individual discoverers. After it was discovered in 2012, some media sources called Comet ISON the "Comet of the Century" and speculated that it might outshine the full Moon. An "Astronomy Now" columnist wrote in September 2012 that "if predictions hold true then Comet ISON will