What is the origin of 'sleep tight'? One of the mysteries of the English language finally explained.
The moon doesn't glow in a very real sense. It reflects the Sun's light. (Or the Earth's light if you're not on Earth and in the right position.) As Quora User says, the moon has a high albedo. So it reflects pretty well.
Confidence votes 5.0K. It is when on Earth we see one quarter of the moon lit up. The surface of the moon is always illuminated a little over 50% by the sun but what we see of it on Earth varies as it revolves around the Earth from none (New moon) to about 50% (Full moon) One quarter is in between.