The moon phase that appears when the Moon is between the Earth and the Sun is a New Moon.

Here's why:

* Lunar Phases: The different phases of the Moon we see are caused by the changing angles of sunlight reflecting off its surface as it orbits Earth.

* New Moon: During a New Moon, the Moon is positioned directly between the Earth and the Sun. Because the sunlit side of the Moon is facing away from Earth, we can't see it. This is why it appears dark in the sky.