What is the scientific explanation of the moon's absence?

Answer 1

The moon doesn't always rise and set at night, sometimes it rises and sets during the day.

This is dependent on the phase of the moon.

The moon circles the earth once every 28 days.

The closer to full the moon is, the more hours it spends in the sky at night, because it is on the opposite side of the earth as the sun. That's why it is full - the sun is behind you, lighting the moon in front of you. A completely full moon will rise as the sun sets, and set as the sun rises, and will be visible all night.

The closer to "new" the moon is, the fewer hours it spends in the sky during the night, and the more time it spends during the day because it is on the SAME side of the earth as the sun. It appears "new" because the sun is behind it, lighting the far side of the moon. A completely new moon will rise and set with the sun, and will only be visible in the day.. or briefly at dusk.

A half-moon is up half the day and half the night. If you don't see a half-moon at night, it has either already set or hasn't risen yet.