Why is it impossible to see a crescent moon at midnight?
A crescent moon is only possible when the Moon is at an angle to the Sun less than 90 degrees. When it is midnight, the Sun is 90 degrees below both the horizon measuring both east and west, so if the phase of the Moon was crescent at that time, it would be below the horizon and you wouldn’t be able to see it. You can test this idea for example with a flashlight (to represent the Sun), a tennis ball (to represent the Moon) and your head (to represent the Earth). Try putting the flashlight right behind your head and then, without moving your head, try to get the tennis ball into a position where you can see it, but the illuminated part of its surface is a crescent. You can’t do it; the angles just don’t work.
