Description: 当两个天体在观测者看来排成一条直线或接近一条直线，并且在天空中位于相反方向时，谓之为“冲”。观测者并不需要能同时看到这两个物体。例如，在满月时，太阳、地球上的观测者和月亮排成一线，因此月亮可见部分的表面完全被太阳照亮——除非三者完美对齐，在这种情况下会发生月食。当行星、彗星或小行星处于冲时，通常是指与太阳和地球上的观测者的关系。当行星处于冲时，它将显得特别明亮，在移动方向上出现“逆行”（因为地球在其较内侧轨道上移动得更快），并且离地球特别近。

Related Terms:

• 合
• 月相
• 凌

Term and definition status: The original definition of this term in English have been approved by a research astronomer and a teacher
The translation of this term and its definition is still awaiting approval

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