Moon Phases Postcard. Lunar Phases. Very popular & useful postcard. 4" X 6" size.  2023 Edition Now in Stock.

Never know when the next full moon is due or if the moon is currently waxing or waning? Our handy lunar reference card graphically details daily moon phases for the 2023 calendar year. A great magickal reference, the moon phases reference card has a convenient 4" by 6" size and can also be used as a postcard.

The following information is NOT printed on this postcard:

A lunar phase or phase of the moon is the appearance of the illuminated portion of the Moon as seen by an observer, usually on Earth. The lunar phases vary cyclically as the Moon orbits the Earth, according to the changing relative positions of the Earth, Moon and Sun. One half of the lunar surface is always illuminated by the Sun (except during lunar eclipses), and hence is bright, but the portion of the illuminated hemisphere that is visible to an observer can vary from 100% (full moon) to 0% (new moon).

Lunar phases are the result of looking at the illuminated half of the Moon from different viewing geometries; they are not caused by the shadow of the Earth or umbra falling on the Moon's surface (this occurs only during a lunar eclipse). The Moon exhibits different phases as the relative geometry of the Sun, Earth and Moon changes, appearing as a full moon when the Sun and Moon are on opposite sides of the Earth, and as a new moon (dark moon) when they are on the same side.

The phases of full moon and new moon are examples of syzygies, which occur when the Earth, Moon and Sun lie (approximately) in a straight line. The time between two full moons (a Lunar month) is about 29.53 days (29 days, 12 hours, 44 minutes) on average (hence, the concept of a timeframe of a period of time of an approximated month was derived). This synodic month is longer than the time it takes the Moon to make one orbit about the Earth with respect to the fixed stars (the sidereal month), which is about 27.32 days. This difference is caused by the fact that the Earth-Moon system is orbiting about the Sun at the same time the Moon is orbiting about the Earth.