This site is a good resource for understanding the Galactic-Winter Solstice Sun alignment from the astronomical and physical perspective. The Mayans were apparently not concerned with complete astronomical accuracy, which is why i sometimes cringe a bit after hearing too much about the specific date of "2012" constantly.
This is a period or cycle, and as John Major Jenkins shows, its a period of some 36 years stretching from about 1980 to 2016, with the mid point, 1998 being the year of exact, center point alignment.
2012 then becomes a bit moot in a sense, but what's interesting about this more specific date is that its also corresponds to the much smaller Solar cycle peaking, wherein the Sun should be its most active over a 11 year span.
So maybe, this specific year is more specifically important...but don't expect sudden fire works exactly on December....
Anyways, here is the link:
http://edj.net/mc2012/whatisGA.htm Jenkins has done some good and original research with this whole Galactic-Solar alignment issue, but as far as the rest of his info goes, i think he has his head way too much in the clouds as regards future probabilities.
He seems to want to ignore any probable catastrophic type occurrences. Way too unrealistically idealistic, overly Libran, Neptunian, Lunar, and Sagiittarian and not enough Capricorn, Jupiter, and Aquarius. At least in my opinion.
It would be rather unfortunate for humanity if Jenkins got his way and convinced everyone interested in same that there will not be any significant physical/geological, climate, and economic upheavals, and then when the time comes not enough are holistically prepared for such things actually happening.
That would be unfortunate indeed, which is probably why sources who do actually know, like the guidance energies that came through or communicated with Rosiland McKnight, Cayce, Monroe, Moen, and many indigenous and biblical prophets, spoke otherwise about the triune nature of the Changes, which very much includes rather probable material challenges and changes.