Earth is the only one of the inner planets with a large satellite, the orbit of which is neither in the equatorialplane of Earth nor in the plane in which the other planets lie.
地球是内行星中唯一一个有大卫星的，它的轨道既不在地球的赤道平面上，也不在其他行星所在的平面上。
2
Because of its oblate shape, the moment of inertia of the earth is a maximum about the polar axis and minimum about an axis in the equatorialplane.
由于地球是扁球体，绕极轴惯量矩最大，而绕在赤道面内的轴的惯量矩最。
3
All geostationary satellites orbit the earth in the equatorialplane at a height of 35,785 km above the equator and stand still at a fixed azimuth and altitude for an observer on the earth surface.