Mayan Calendar End Date
In astronomical terms, the Sun conjuncts the intersection of the Milky Way and the plane of the ecliptic. The Milky Way, as most of us know, extends in a general north-south direction in the night sky. The plane of the ecliptic is the track the Sun, Moon, planets and stars appear to travel in the sky, from east to west. It intersects the Milky Way at a 60 degree angle near the constellation Sagittarius.
The cosmic cross formed by the intersecting Milky Way and plane of the ecliptic was called the Sacred Tree by the Maya. The trunk of the tree, the Axis Mundi, is the Milky Way, and the main branch intersecting the tree is the plane of the ecliptic. Mythically, at sunrise on December 21, 2012, the Sun - our Father - rises to conjoin the center of the Sacred Tree, the World Tree, the Tree of Life..
This rare astronomical event, foretold in the Mayan creation story of the Hero Twins, and calculated empircally by them, will happen for many of us in our lifetime. The Sun has not conjoined the Milky Way and the plane of the ecliptic since some 25,800 years ago, long before the Mayans arrived on the scene and long before their predecessors the Olmecs arrived. What does this mean?
Due to a phenomenon called the precession of the equinoxes, caused by the Earth's wobble that lasts almost 26,000 years, the apparent location of the Winter Solstice sunrise has been ever so slowly moving toward the Galactic Center. Precession may be understood by watching a spinning top. Over many revolutions the top will rise and dip on its axis, not unlike how the Earth does over an extremely long period of time. One complete rise and dip constitutes the cycle of precession.
The Mayans noticed the relative slippage of the positions of stars in the night sky over long periods of observation, indicative of precession, and foretold this great coming attraction. By using an invention called the Long Count, the Mayans fast-forwarded to anchor December 21, 2012 as the end of their Great Cycle and then counted backwards to decide where the calendar would begin. Thus the Great Cycle we are currently in began on August 11, 3114 B.C. But there's more.
The Great Cycle, lasting 1,872,000 days and equivalent to 5,125.36 years, is but one fifth of the Great Great Cycle, known scientifically as the Great Year or the Platonic Year - the length of the precession of the equinoxes. To use a metaphor from the modern industrial world, on Winter Solstice A.D. 2012 it is as if the Giant Odometer of Humanity on Earth hits 100,000 miles and all the cycles big and small turn over to begin anew. The present world age will end and a new world age will begin.
Over a year's time the Sun transits through the twelve houses of the zodiac. Many of us know this by what "Sun sign" is associated with our birthday. Upping the scale to the Platonic Year - the 26,000 year long cycle - we are shifting, astrologically, from the Age of Pisces to the Age of Aquarius. The Mayan calendar does not really "end" in 2012, but rather, all the cycles turn over and start again, vibrating to a new era. It is as if humanity and the Earth will graduate in the eyes of the Father Sun and Grandmother Milky Way.
source: Crawford 2000