Planetary Alignment in 2012?
We often hear that the planets of the solar system will be aligned on December 21, 2012, the date of the end of the Long Count of the Mayan calendar (according to the most widely accepted interpretation: the GMT correlation).
Since we know very accurately the locations and the orbits of the solar system planets, we can very easily calculate their configurations years (and even centuries) in advance. Let's have a look.
On the NASA website, we can use an online tool called the Solar System Simulator, which gives us the location of the planets for a given date and time, and from different points of view. For December 21, 2012, there is no planetary alignment in the solar system.
We can also double-check this result with this sky map generator at Fourmilab.
We can see that a minor alignment of Jupiter, the Earth and Mercury will occur on December 17, 2012, and that Jupiter, the Earth and Venus will be aligned on December 23, 2012. However, these minor planetary alignments are quite frequent, and they don't have any impact on the Earth because their gravitational attraction is extremely small.
While you're at it, you could see some past major planetary alignments, like the one that happened on May 5, 2000 (the Sun, Mercury, Venus, The Earth, Mars, Jupiter, and Saturn were aligned) or the one that occurred on February 4, 1962. During these two major planetary alignments, absolutely no impact (and even less catastrophes) was measured.
The next major planetary alignment will happen on September 8, 2040, while Mercury, Venus, Mars, Saturn and the Moon will be located in a small portion of the sky.