Why can't we see the moon during the new moon phase?
The side facing the Earth is not receiving any sunlight.
The moon does not create light, it reflects sunlight. When the moon lies between the Earth and the Sun, it is only the back side of the moon that is light by the Sun. In this situation the side of the moon facing the Earth is not able to reflect any light at all and appears dark. This diagram should make it a little easier.
The difference between a new moon and a solar eclipse is during a solar eclipse, the moon is exactly in position to fully block the sun during the day. This diagram should show this.
Thanks to Jay G. for pointing out the previous error, this should correct it.
During the new moon phase the far side of the moon is illuminated and it in the daytime sky.
A new moon occurs when the Moon is between the Sun and the Earth. The far side of the Moon is in full sunlight and the near side of the Moon receives no sunlight.
The new moon is also in the daytime sky. Sunlight illuminates the atmosphere so much that the dark face of the new moon can't be seen.
Many people associate the Moon with nighttime. In fact the Moon is visible during daytime for about half of the month. It is best seen in the morning or evening depending upon the position of the Moon.