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Lunar Phase

Lunar Phase
The phase and libration of the Moon for 2013 at hourly intervals, with music, titles and supplemental graphics. Animation of the Moon as it cycles through its phases, as seen from the Northern Hemisphere. The apparent wobbling of the Moon is known as libration. The apparent change in size is due to the eccentricity of the lunar orbit. The principal lunar phases are new moon, first quarter moon, full moon and last quarter moon. These are the instants when, respectively, the Moon's apparent geocentric celestial longitude minus the Sun's apparent geocentric celestial longitude is 0°, 90°, 180° and 270°. Names of lunar phases[edit] Phases of the Moon, as seen looking southward from the Northern Hemisphere. In Western culture, the phases of the Moon have been given the following names, in sequential order: A crescent moon above Earth's horizon is featured in this image photographed by an Expedition 24 crew member. Crescent Moon taken by MPG/ESO 2.2-meter telescope at La Silla. The Calendar[edit]

http://en.wikipedia.org/wiki/Lunar_phase

Lunar Calendar A lunar calendar is a calendar that is based on cycles of the lunar phases. Because there are slightly more than twelve lunations (synodic months) in a solar year, the period of 12 lunar months (354.37 days) is sometimes referred to as a lunar year. A common purely lunar calendar is the Islamic calendar or Hijri Qamari calendar. A feature of the Islamic calendar is that a year is always 12 months, so the months are not linked with the seasons and drift each solar year by 11 to 12 days. It comes back to the position it had in relation to the solar year approximately every 33 Islamic years.

Calendar A calendar is a system of organizing days for social, religious, commercial or administrative purposes. This is done by giving names to periods of time, typically days, weeks, months, and years. A date is the designation of a single, specific day within such a system. Periods in a calendar (such as years and months) are usually, though not necessarily, synchronized with the cycle of the sun or the moon. moon calendar <div style="text-align:center; color:red; font-size:large; font-weight:bold;"> Note: you seem to have JavaScript disabled.<br />This page requires it to be enabled for full functionality. </div>

Moon Phases Why does the Moon have phases? At the new Moon phase, the Moon is so close to the Sun in the sky that none of the side facing Earth is illuminated (position 1 in illustration). In other words, the Moon is between Earth and Sun.

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