Running Late to the Planet Party
Much of the confusion that's muddied the field and allowed for the invention of various planetary and galactic alignment theories stems from the fact that while explaining and understanding the actual astronomical landscape takes a little effort, pandering to people's fear and paranoia does not. Understanding the reality of the situation involves a look at how different aspects of the Milky Way and our solar system are scientifically defined and spatially assessed -- served, of course, with a healthy dollop of common sense.
Let's examine the planetary alignment theories in particular. If you were looking down on our solar system from above, what's considered a planetary alignment -- also known as a conjunction event -- is when it looks like some or all of the planets are forming a more-or-less straight line. The sun can either be at one end, or somewhere along the middle. Assuming it was the former, though, if you were viewing this alignment from Earth, you would see the planets involved clustered together in one quadrant of the night sky. And if you shot a somewhat wobbly arrow from the sun, it would pass through every planet. "Alignment," however, doesn't mean perfect. It's often a little chaotic: more like a loose collection since the planets are considered aligned even when they're several degrees apart in the night sky -- but that's the sight.
What the doomsday theories typically suggest is that the gravitational pull of the other aligned planets would trigger cataclysmic disasters on Earth (or on the sun, and in turn on Earth). Perhaps their combined tugs would cause tidal changes and flooding, or pole shifts and earthquakes. Problem is, even if the Earth and the sun and all the other planets in our solar system aligned with each other on Dec. 21, 2012, that wouldn't set the stage for any special events -- and especially any disastrous events -- to occur. It would just be an interesting item of note, nothing to get in a panic about.
That's because the distances between planets are just too great to cause any events. Even if every planet in the solar system ganged up against Earth on the other side of the sun, it wouldn't create even a minor effect on us. And when the planets do align on our side of the white picket fence, their effect is also negligible. And forget the idea that there's one "special" alignment that's never happened before. Major planetary alignments are relatively rare in terms of human lifetimes, but they're far from uncommon in the big scheme of things. If the Earth hasn't already been thrown asunder at this point, we're certainly not in for any surprises now.
But when it comes to 2012 in particular, a major planetary alignment isn't in the cards, and certainly not on Dec. 21. These rare grand conjunction events only happen every couple of decades and the 2010s aren't one of them. One major alignment occurred in 1962, for example, and two others happened during 1982 and 2000. Not-so-amazingly, Earth pulled through.