Why can you see the colour of the sky within the shape of a crescent or half moon?


If the moon is a complete sphere, but the sun only shines on certain parts of it until the full moon, why can you see the colour of the sky? For example, if I see a half moon during the day, the other side of it appears blue as well. Shouldn’t the other half just appear as a dark space, since the rest of the moon is still there, blocking the sky?

In: Physics

The sky is between you and the moon. Not enough light bounces off the dark side to overpower the blue sky, which is caused by sunlight interacting with the atmosphere. Space is not blue.

The blue of the sky is from the air, and the moon is outside the atmosphere. Therefore the blue is closer to you on the ground than the moon and the dark part of the moon is behind it.