Stardate.org features a moon phase calendar with pictorial representation of the moon's phase on each day allowing you to determine the current moon phase. The calendar also features a search option that allows users, as of 2015, to determine the moon's phase on any date between 1951 and 2016.Continue Reading
Astronomers see the moon undergo phases because of the way it orbits the earth. Although the Moon orbits the Earth every 27.3 days, the lunar phase cycle takes 29.5 days to complete, as the moon spends about two days catching up with the Earth's path around the sun. This relationship causes the appearance of a new moon and half moon at near-monthly intervals when the Earth casts a shadow over its celestial neighbor.
When the moon is close enough to the sun such that its earth-facing side is not illuminated at all, the moon is in its new moon phase. When the moon is at a right angle to the earth respective to the sun, it is in the half moon phase. A full moon occurs when the earth travels between the moon and the sun, allowing the sun to fully illuminate the celestial object in the earth's outward-facing night sky.Learn more about Our Moon