In particular, the speed of the Moon around the Sun will never be negative, so the Moon will never loop backwards.

特别是月球绕行太阳的速度决不可能是负的，所以月球永远不会向后打转。

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A NASA Solar and Heliospheric Observatory image of the Sun shows a giant magnetic loop (lower left) filled with glowing, hot gas blasting away from the Sun.

美国宇航局太阳和太阳风层探测器拍摄的太阳图像，显示出巨大的磁场环(左下)，充满猛烈脱离太阳的流动热气。

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Moreover, the sun position in the sky is obtained by astronomic algorithms in the case of open loop.

由天文历法来计算太阳在天空中的位置。

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