Blue Moon August 31, 2012; Last One for 3 Years

In a rare lunar event, the month of August has been deemed the Blue Moon Month where sky gazers will enjoy two full moons before the month is over.

On Friday, Aug. 31, be sure not to miss the month's second full moon called the blue moon.

A blue moon, being the second of two full moons within any given month, is a rare occurrence; hence the phrase "once in a blue moon" which indicates the rarity of an event.

The first full moon during the month occurred on Aug. 1, but even if stargazers missed the bright sky then, they can enjoy the last blue moon that will occur for the next three years. The blue moon will reach its full phase at 9:58 a.m. EST Friday.

Blue moons exist due to our calendar months being imperfectly synched to the lunar months. It takes 29.5 days for the moon to orbit Earth, during which sky watchers observe all of its phases. All calendar months, aside from February, have 30 or 31 days, resulting in the occasional two full moons within a single month.

While blue moons are rare, they can be predicted to take place every three years or so, with the next one scheduled to take place in July 2015.

The name of the event comes from the colors the moon takes on from time to time due to different conditions. After volcanic activity or forest fires, the moon can appear to take on a bluish or sometimes lavender coloration. This is because of soot and ash particles deposited high up into the Earth's atmosphere.

Moreover, smoke from a large wildfire created a blue moon across eastern North America in late September 1950, according to CBS News.

In addition to the Blue Moon Month of August, 2012 has been an exciting year for sky watchers, as May saw a Supermoon where the full moon appeared larger due to its closeness to the Earth.

While the moon on May 5 reached its peak fullness, its perigee occurred, meaning the moon reached its closest point to Earth in orbit. The rare combination made for the moon's appearance to be especially pronounced.