When the moon passes between the Earth and the sun, it casts a shadow with two parts, represented by different shades in this animation. The darker, inner shadow is called the "umbra." That's where …
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When the moon passes between the Earth and the sun, it casts a shadow with two parts, represented by different shades in this animation. The darker, inner shadow is called the "umbra." That's where all of the sun's light is blocked by the moon. Notice that the umbra becomes smaller further away from the moon. The less dark, outer shadow is called the "penumbra," where the sun's light is only partially blocked.
