I've mentioned this previously - the ancient Mayans thought that Venus was the god of war. The transit of Venus, as occurred today, was likely a really big deal for them. Interestingly, the next transit of Venus is due for 2012... which also happens to be the "end date" of the Mayan calendar.
December 21st, 2012 A.D. represents the end of the "Long Count" or baktun: a period of time consisting of 144,000 days. Larger than that is the "Great Cycle" consisting of 13 baktuns - 1,872,000 days, or 5,125.36 years. It's postulated that the Mayans figured out that there was going to be a significant astronomical event on that date (involving the sun and Venus and so on), and around 300 B.C. they calculated backwards to identify the "start date" of the world.
Pretty neat.
Edit: Wikipedia entry on Mayan calendar - this notes that the end date could also be 12/23/2012... it's the Winter Solstice in any case.![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}