The Oort cloud (/ ɔːr t, ʊər t /), named after the Dutch astronomer Jan Oort, sometimes called the Öpik–Oort cloud, is a theoretical cloud of predominantly icy planetesimals proposed to surround the Sun at distances ranging from 50,000 and 200,000 AU (0.8 and 3.2 ly). read more
Identifying the Oort Cloud In 1950, Dutch astronomer Jan Oort suggested that some of the comets entering the solar system come from a cloud of icy bodies that may lie as far as 100,000 times Earth's distance from the sun, a distance of up to 9.3 trillion miles (15 trillion kilometers). read more