The Moon exhibits different phases as the relative position 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 2.8 seconds) on average (hence, the concept of the time frame of an approximated month was derived). This
Synodic month is longer than the time it takes the Moon to make one orbit around the Earth with respect to the fixed stars (the
Sidereal month), which is about
27.32 days (27 days, 7 hours, 43 minutes 11.5 seconds).This difference is caused by the fact that the Earth-Moon system is orbiting around the Sun at the same time the Moon is orbiting around the Earth.
The orbit of the moon is very nearly circular (eccentricity 0.05) with a mean separation from the earth of about 384,000 km. which is about 60 earth radii. The plane of the orbit is tilted about 5 degrees with respect to the plane.
Priming - New Moon to 1st Quarter (1-3) / Full Moon to 3rd Quarter (5-7)
Lagging – 1st Quarter to Full Moon (3-5) / 3rd Quarter to New Moon (7-1)
Waxing Moon – The Moon between new and full when its visible part is increasing.
Waning Moon – The moon between full and new and when its visible part is decreasing.
Harvest Moon – The full moon nearest the autumnal equinox.
Hunters Moon – The full moon one month after the autumnal equinox.
Neap Tides (1st Quarter or 3rd Quarter)
Spring Tides (New Moon and Full Moon)
Position
|
Phase
|
Age (days)
|
Rise
|
| 1 | New Moon | 0 | 6 AM |
| 2 | 1st Quarter | 7 1/4 | 12 NN |
| 3 | Full Moon | 14 1/2 | 18 PM |
| 4 | 3rd Quarter | 21 3/4 | 24 PM |
