Oort Cloud

Meanings

1. The Solar System's Oort cloud, extending from 50,000 to 100,000 astronomical units (approximately 1 light year) from the sun; supposedly the source of most comets around the Solar System.

1. Alternative letter-case form of Oort Cloud (“the Solar System's Oort cloud”).

1. A roughly spherical region of space composed of comet-like bodies and other minor planets and asteroids that orbit distantly in a planetary system.

Etymology

Named after the Dutch astronomer Jan Hendrik Oort, who revived the Estonian astronomer Ernst Öpik’s idea from 1932 of a reservoir of long-period comets in the form of an orbiting cloud at the outermost edge of the Solar System in 1950 to resolve a paradox about the origin of comets.