Well, it's that time of year again for some serious dancing. And no, I’m not referring to the televised celebrity dance competitions! I mean the light shows in the northern winter sky where the sky appears to dance with color. That's right, the Aurora Borealis, or Northern Lights.

An Aurora is a beautiful natural phenomenon that often occurs in the polar regions of Earth. It appears as colorful clouds and rays of green and red (and sometimes blue) light that dance across the sky. The Aurora Borealis and Aurora Australis (Latin for "northern" and "southern" dawn, respectively) occur in symmetric ovals centered on the northern and southern magnetic poles of Earth. Weatherplus.com has a great blog entry on how Auroras are formed, along with a slideshow of Northern Lights photos.

Those of us who live too far south to catch the Northern Lights from the comfort of home have to travel north to see them. Sure, you could head south in summer to catch the Aurora Australis -- but by south, I mean all the way to Antarctica. Most Americans find it easier and less expensive to catch the Northern Lights.

Though the further north you travel, the better your chance of seeing the Aurora Borealis, nothing is guaranteed when it comes to nature. So here are some tips to improve your odds if you're planning a Northern Lights trip.

1. Sunspots Are Good. Auroral activity correlates with the activity of the sun, which changes according to an 11-year solar cycle. In general, the more active the sun, the greater the number of auroras. (Keep in mind that bright and active auroras can be observed at any time during the solar cycle.) For a chart showing the solar cycle and sunspot activity, click here.

2. Clean And Clear. Even if you're far from city lights, air pollution can affect the sky's clarity. The further away you are from big cities, the better your chances of seeing the Northern Lights.

3. Dark Of The Moon. The light of the silvery moon can be beautiful, but it can also ruin the intensity of an aurora. Plan your trip for when the moon is new or waning. Click here for a calendar of the moon's phases in 2007.

4. The 27-Day Rule. If your vacation schedule is flexible, find out when the last auroral display was for your intended Northern Lights get-away. It takes the sun 27 days to rotate one time around its axis, so 27 days after an aurora display, the active region on the sun that caused the aurora will face Earth again. Although solar activity in that region on the sun might have decreased in the mean time, there is still a greater chance of aurora 27 days after the last period of increased auroral activity.

Not much for planning trips to freezing far-away locales? Keep an eye on the solar cycle -- when it's active, you can sometimes see the Northern Lights in parts of the United States!