Related Searches
on Ask.com
Libration - 4 dictionary results
li⋅bra⋅tion
[lahy-brey-shuh
n] 
–noun Astronomy.
| a real or apparent oscillatory motion, esp. of the moon. |
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2009.
Cite This Source
Based on the Random House Dictionary, © Random House, Inc. 2009.
Cite This Source
|
Link To Libration
| li·bra·tion (lī-brā'shən) n. A very slow oscillation, real or apparent, of a satellite as viewed from the larger celestial body around which it revolves. [Latin lībrātio, lībrātiōn-, oscillation, from lībrātus, past participle of lībrāre, to balance, from lībra, balance.] li·bra'tion·al adj., li'bra·to'ry (-brə-tôr'ē, -tōr'ē) adj. |
The American Heritage® Dictionary of the English Language, Fourth Edition
Copyright © 2009 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Cite This Source
Copyright © 2009 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Cite This Source
Libration
Li*bra"tion\ (l[-i]*br[=a]"sh[u^]n), n. [L. libratio: cf. F. libration.]1. The act or state of librating. --Jer. Taylor. 2. (Astron.) A real or apparent libratory motion, like that of a balance before coming to rest. Libration of the moon, any one of those small periodical changes in the position of the moon's surface relatively to the earth, in consequence of which narrow portions at opposite limbs become visible or invisible alternately. It receives different names according to the manner in which it takes place; as: (a) Libration in longitude, that which, depending on the place of the moon in its elliptic orbit, causes small portions near the eastern and western borders alternately to appear and disappear each month. (b) Libration in latitude, that which depends on the varying position of the moon's axis in respect to the spectator, causing the alternate appearance and disappearance of either pole. (c) Diurnal or parallactic libration, that which brings into view on the upper limb, at rising and setting, some parts not in the average visible hemisphere.
Webster's Revised Unabridged Dictionary, © 1996, 1998 MICRA, Inc.
Cite This Source
Cite This Source
libration
in astronomy, an oscillation, apparent or real, of a satellite, such as the Moon, the surface of which may as a consequence be seen from different angles at different times from one point on its primary body
Learn more about libration with a free trial on Britannica.com.
Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
Cite This Source
Cite This Source
Copyright © 2009, Dictionary.com, LLC. All rights reserved.
