The New Moon phase is not visible to observers on Earth because the Moon is positioned between the Sun and Earth.

Here's why:

* Sunlight and Shadows: The Moon shines because it reflects sunlight. During the New Moon phase, the Sun illuminates the side of the Moon that is facing away from Earth.

* Alignment: As the Moon orbits Earth, it aligns with the Sun in such a way that the Sunlit side of the Moon is facing away from us. This means the side facing Earth is in shadow.

* Not Completely Dark: The New Moon is not completely invisible. Sometimes, we can see a faint glow from the Moon, known as earthshine. This is sunlight reflected off the Earth and then reflected back to us by the Moon.

So, while the New Moon doesn't appear as a bright disc in the sky like other phases, it's still there, just hidden in the Sun's light.