Comet Shoemaker–Levy 9 the Cretaceous period is generally thought to have been caused by the Cretaceous–Paleogene impact event, which created the Chicxulub crater, demonstrating that impacts are a serious threat to life on Earth. Astronomers have speculated that without Jupiter to mop up potential impactors, extinction events might have been more frequent on Earth, and complex life might not have been able to develop. This is part of the argument used in the Rare Earth hypothesis. In 2009, it was shown that the presence of a smaller planet at Jupiter's position in the Solar System might increase the impact rate of comets on
Carolyn S. Shoemaker Rittenhouse Medal of the Rittenhouse Astronomical Society in 1988 and the Scientist of the Year Award in 1995. The Hildian asteroid 4446 Carolyn, discovered by college Edward Bowell at Lowell Observatory in 1985, was named in her honor. Carolyn Shoemaker is credited by the Minor Planet Center with the discovery of 377 numbered minor planets made between 1980 and 1994. Carolyn S. Shoemaker Carolyn Jean Spellmann Shoemaker (born June 24, 1929) is an American astronomer and is a co-discoverer of Comet Shoemaker–Levy 9. She once held the record for most comets discovered by an individual. Carolyn Jean Spellmann was born