All Sources -
Updated Media sources (1) About encyclopedia.com content Print Topic
libration The slow oscillation of a satellite, as seen from the planet around which it revolves. One libration is due to a parallax effect: e.g., because of the rotation of the Earth, more of the eastern limb of the Moon is visible at moonrise, while more of the western limb can be seen at moonset. In the Earth—Moon system, a second libration is that of lunar longitude, with a monthly period, since the Moon's revolution around the Earth sometimes exceeds and sometimes lags behind its axial rotation, and the third lunar libration is of latitude, due to the 6° inclination of the lunar equator to its orbital plane, so that more of the polar regions become visible when the Moon is north or south of the ecliptic.
libration oscillation, balancing. XVII. — L. lībrātiō, -ōn—, f. lībrāre balance, f. lībra pound weight, scales; see -ATION.
More From encyclopedia.com
Tides , Tides Introduction A tide is the alternating rise and fall in sea level that occurs at marine coastal regions each day. The sea level change is cause… Phase , phase / fāz/ • n. 1. a distinct period or stage in a process of change or forming part of something's development: the final phases of the war| [as a… Moon (satellite) , Moon The Moon was the subject of widespread folklore in ancient times. While the brightest object in the night sky, it is not so bright that its surf… Moon , The Moon was the subject of widespread folklore in ancient times. While the brightest object in the night sky, it is not so bright that its surface t… Angular Momentum , angular momentum The momentum of a body rotating in a plane around a point. It is formally the product of the mass of the body, the radius of the orb… Warren Moon , Moon, Warren 1956– Professional football player For more than ten years Warren Moon has been a starting quarterback in the National Football League,…
You Might Also Like