Oort Cloud

== English == === Alternative forms === Oort cloud === 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. === Pronunciation === IPA(key): /ˈɔːrt klaʊd/ Hyphenation: Oort Cloud === Proper noun === the Oort Cloud (astronomy) 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. ==== Synonyms ==== Öpik-Oort Cloud ==== Translations ==== === Further reading === Oort Cloud on Wikipedia.Wikipedia