It turns out, however, that there are 365.24219 days in an astronomical "tropical" year-defined as the time it takes the sun, as seen from Earth, to make one complete circuit of the sky.

尽管这样，实际上在天文上一回归年中有365.24219天——一回归年指的是由地球上观察，太阳在天空运行一整个圆周所用的时长。

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Its star is a red giant - a massive star near the end of its life. It is too dim to see in the night sky from Earth without a telescope.

Gliese 581是一颗已经接近生命终点的红巨星，星光十分暗淡，在没有天文望远镜的情况下，从夜空中根本无法看到。

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Heraclitus's game is the beginning of the West on game theory, Plato was the first to recall the game from the sky the earth.

赫拉克利特的游戏说是西方关于游戏理论的开端，柏拉图是第一个把游戏从天上召回地上的人。

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Both are designed to look at hundreds of thousands of galaxies, and to pinpoint their location in the sky and their distance from Earth.

ECONOMIST: Astronomy