(astronomy) a real or apparent slow oscillation of a moon or satellite;
"the libration of the moon"
例句
Low noise, libration, power consuncption. 整机噪声小、振动小、功耗比小。
When you fight for oil,you call that libration. 我们买石油，你们说那是殖民和种族灭绝；
Notice no heavier strike or libration in course of moving. 注意在移动过程中，不得有较重的撞击与振动。
Owing to the phenomenon of libration it is possible to observe up to 60% of the total lunar surface. 由于天平动的现象，我们可能观测到月球总面积的60%25。
Through optimizing design to fulfill strong steel structure, and to ensure the machine weaving abb with high speed, strong power and small libration. 通过优化设计而实现的高钢性机架构造,保证了织机高速、强劲、低振动的稳定打纬。
A possibility of applications of proposed algorithms to control libration angle of satellite was illustrated. 提出控制卫星天平动角的算法，用图示对该算法作了说明。
