Oort cloud
noun Astronomy.
a region of the solar system far beyond the orbit of the dwarf planet Pluto in which billions of comets move in nearly circular orbits unless one is pulled into a highly eccentric elliptical orbit by a passing star. Compare Kuiper belt.
Origin:
1975–80; after Dutch astronomer Jan Hendrik Oort (1900–1992), who proposed its existence
1975–80; after Dutch astronomer Jan Hendrik Oort (1900–1992), who proposed its existence
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2013.
Cite This Source
Based on the Random House Dictionary, © Random House, Inc. 2013.
Cite This Source
|
Link To Oort cloud
Etymonline
Word Origin & History
Oort cloud
in reference to the hypothetical cloud of small objects beyond Pluto that become comets, proposed 1949 by Du. astronomer Jan Hendrick Oort (1900-1992), and named for him by 1968.
Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
Cite This Source
00:10
Oort cloud
is always a great word to know.
So is bezoar. Does it mean:
| a calculus or concretion found in the stomach or intestines of certain animals, esp. ruminants, formerly reputed to be an effective remedy for poison. |
| a screen or mat covered with a dark material for shielding a camera lens from excess light or glare. |
American Heritage
Science Dictionary
Oort cloud  (ôrt) Pronunciation Key
A sphere-shaped mass of more than 100 billion comets that makes up the outer edge of the solar system, surrounding the Kuiper belt and the planets. Some comets from this area are drawn into the inner solar system by passing stars and other forces and take more than 200 years to make one complete orbit of the Sun. Compare Kuiper belt. |
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Image for Oort cloud
Nearby Words
Copyright © 2013 Dictionary.com, LLC. All rights reserved.
