In the mid-1990s, esoteric author John Major Jenkins asserted that the ancient Maya intended to tie the end of their calendar to the winter solstice in 2012, which falls on December 21. This date was in line with an idea he terms the galactic alignment
In the Solar System, the planets and the Sun share roughly the same plane of orbit, known as the plane of the ecliptic. From our perspective on Earth, the ecliptic is the path taken by the Sun across the sky over the course of the year. The 12 constellations which line the ecliptic are known as the zodiac and, through the year, the Sun passes through each constellation in turn. Additionally, over time, the Sun's annual passage appears to recede counterclockwise by one degree every 72 years. This movement is attributed to a slight wobble in the Earth's axis as it spins. As a result, approximately every 2160 years, the constellation visible on the early morning of the spring equinox changes. In Western astrological traditions, this signals the end of one astrological age (currently the Age of Pisces) and the beginning of another (Age of Aquarius). Over the course of 26,000 years, the precession of the equinoxes makes one full circuit around the ecliptic.
Astronomers argue that the galactic equator is an entirely arbitrary line, and can never be precisely determined because it is impossible to say exactly where the Milky Way begins or ends.
Jenkins claims he drew his conclusions about the location of the galactic equator from observations taken at above 11,000 feet, which is higher than any of the Maya lived. Furthermore, the precessional alignment of the Sun with any single point is not exclusive to a specific year, but takes place over a 36-year period, corresponding to its diameter. Jenkins himself notes that, even given his determined location for the line of the galactic equator, its most precise convergence with the centre of the Sun already occurred in 1998