Oort cloud

noun
\ ˈȯrt- How to pronounce Oort cloud (audio) \

Definition of Oort cloud

: a spherical shell of cometary bodies believed to surround the sun far beyond the orbits of the outermost planets and from which some are dislodged when perturbed to fall toward the sun — compare kuiper belt

First Known Use of Oort cloud

1974, in the meaning defined above

History and Etymology for Oort cloud

Jan Oort †1992 Dutch astronomer

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The first known use of Oort cloud was in 1974

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Cite this Entry

“Oort cloud.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/Oort%20cloud. Accessed 27 Sep. 2020.

More from Merriam-Webster on Oort cloud

Britannica English: Translation of Oort cloud for Arabic Speakers

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