The new Moon is the time when the Moon passes between the Earth and the Sun in the sky, as seen by us. Of course one cannot see the Moon when it passes the Sun–one, the Sun is too bright, and two, the Moon is all dark, since the Sun then shines on the side facing away from Earth. For this reason, the name “new Moon” is also applied to the thin crescent seen soon after the “astronomical new Moon”, shortly after sunset, and that time was used by ancient cultures as the beginning of a new month.
From: http://www-spof.gsfc.nasa.gov/stargaze/Lcalend.htm
The new Moon is the time when the Moon passes between the Earth and the Sun in the sky, as seen by us. Of course one cannot see the Moon when it passes the Sun–one, the Sun is too bright, and two, the Moon is all dark, since the Sun then shines on the side facing away from Earth. For this reason, the name “new Moon” is also applied to the thin crescent seen soon after the “astronomical new Moon”, shortly after sunset, and that time was used by ancient cultures as the beginning of a new month.
Baby butts.