The Earth's axis of rotation is tilted in relation to the ecliptic plane, an imaginary surface through Earth's orbit around the sun.
地球的自转轴与黄道面呈一定角度。黄道面是地球公转轨道所在的一个假想平面。
The angular difference between the astronomical axis and the axis of figure called a "nutation" causes an earth orbit al spirical oscillation known as the famous chandler "wobble".
在天文学轴和形状轴之间的角度差称做“章动”，引起地球轨道螺旋摆动，就是著名的卡南德尔“摆动”。
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