On the other hand, a comparatively warm body with a small surface gravity, like Earth's moon, is unable to hold even the heaviest gas and thus lacks an atmosphere.

另一方面，像地球的卫星这种相对温暖、表面引力较小的天体，它们连最重的气体也无法容纳，因此也没有大气层。

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The Moon, which lacks an atmosphere, receives abundant, energy from the Sun.

月球没有大气层，因而能充分接受阳光照射，有丰富的太阳能可供利用。

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