Oort cloud

Comets are observed to come into the Solar System from all directions, therefore the place from which the comets come is thought by those who believe in a universe that is billions of years old to be a giant sphere surrounding the solar system. This sphere is called the Oort cloud after Jan Oort who postulated its existence in 1945. Thus comets are said to come from the Oort cloud. While some comets are postulated to come to the solar system from closer in, this place is called the Kuiper Belt and it is located past the orbit of Pluto. Kuiper belt objects are suspected by those who believe the universe to be billions of years old to be the source of the Jupiter family, a group of comets whose orbits take them between Jupiter and the sun in a short period of time (3-5 years). Comet Shoemaker-Levy 9 may have been one of those.

Creationist Scientists Perspective

Young Earth Creationist scientists do not believe in the Oort comet cloud and believe there are problems in regards to it existing. [1][2]