When's the next year the planets will align?

First, you'd have to define what YOU mean by "align".

One recent "alignment" that a lot of people accepted to call an alignment, was in early March 1982. This is the "alignment" for which the doomsday predictions were written in 1974 (the hoax was called The Jupiter Effect). These are the predictions that were simply copied-and-pasted into the Big 2012 Hoax.

The 1982 "alignment" simply meant that all the planet were on the same side of the Sun (inside a 180 degree sector). Hardly an alignment.

Astronautics engineer call an "alignment" a placement of planets such that a probe can pass near one and use the "slingshot effect" in order to go on to the next planet at a faster speed, without having to use any fuel.

The last such alignment took place in the 1970s and it happens roughly every 176 years.

http://en.wikipedia.org/wiki/Planetary_Grand_Tour

A real tight alignment (also called a syzygy - with the g meant to be hard as in Garry, not soft as in Gerry). Unfortunately, the word has become as loose in meaning as the word "alignment" so that some people do talk of the syzygy of 1982.

One of the most interesting syzygy took place on March 21, 1894. If you had been able to observe from Saturn, on that day, you would have seen both Venus and Mercury pass in front of the Sun (which, at that distance, is very small).

This would make is an almost perfect alignment of 4 objects (Saturn, Venus, Mercury and the Sun). In astrology, the term is mostly used for alignments "as seen from Earth".

In "doomsday prediction" it can mean whatever you want.

In fact, the alignment of all the planets is a very uncommon experience.

I recall (back in mid-December 2004) that all the naked-eye-visible planets were on the same side of the Earth -- and appeared in order. Just before sunrise, Mercury lower and Venus a bit higher were visible in the east, Earth under our feet, Mars a bit higher than Venus, then Jupiter. Just west of overhead, Saturn was visible.

Last fall (October - November 2010) there was an alignment (conjunction, more precisely) where Jupiter and Uranus danced back and forth several times, as they switched from normal to retrograde motion and back again. The big deal was that Uranus was close enough to Jupiter to be easily found with binoculars -- first time I'd ever seen Uranus, but again, this was a close alignment of two gas giant planets, and all we got was a nice view.

That's typical of a "planetary alignment" -- the planets appear to be lined up in one way or another.

Even when most of them (or a few of them) are aligned more precisely, there are no consequences we've been able to observe.

My astronomy tools don't let me find that answer readily.

Followup -- "There aren't 9 planets any more. Pluto has left the group"

And, just before dawn, you can see 5 planets all at the same time, (if you count seeing the Earth underfoot)... look at this link below:

Since the planets in our solar system don't orbit (travel around the sun) at the same angle, they don't "align" very well. The closest we came to a "grand alignment" was in March of 1982 when all the planets were on the same side of the sun (but they didn't form a straight line). Its not uncommon to have 2 of 3 planets align with each other relatively closely (from our point of view), but they usually just get close to appearing to line up, they don't actually align one behind the other like a line of soldiers.

Planets align all the time. The question is... how many? In what order? Is Earth a part of the alignment? Is it visible with the naked eye?

And even then planets are never really perfectly aligned. But close enough.

On February 5, 1962, Sun, Moon, Mars, Mercury, Jupiter, Venus & Saturn lined up towards Capricorn It was Newmoon on that day and a Solar eclipse too.