July 2015 is all set to witness its second Full Moon. The first one appeared on July 2 and the next one will be arriving this week, on Friday, July 31. According to reports, Friday’s Full Move will be appearing at 10.43 UT (Universal Time) or 6.43 AM EDT.

In modern dialect, the rare occurrence of two Full Moons in the same calendar month is referred to as a “Blue Moon”. This happens due to the synodic period of 29.5 days, which is less than every calendar month except the month of February. For those who don’t know: the term “synodic period” is used for the time the Moon takes for returning to a particular phase. In this case, the synodic period represents the time between two Full Moons.

Blue Moon

The last time our planet witnessed a Blue Moon was around three years back, on August 31, 2012. The next one, on the other hand, will take place on January 31, 2018. The month of July will again have a Blue Moon after 19 years i.e. in 2034. The last July Blue Moon appeared in 2004.

The phrase “once in a blue Moon” is used to depict rarity. However, the above statistics prove that it’s not as rare as believed by many. It’s quite frequent and takes place once in every two to three years.

It’s already known why the Full Moon of July 31 will be called a Blue Moon, but can the Moon be blue in color?

Must Read: July 31st will bring the rare Blue Moon madness

Previous literature suggests that the world witnessed a Blue Moon way back in 1883. The blue hued Moons were not necessarily Full Moons. On some occasions, they appeared on the night sky as a Half Blue Moon or a crescent.

There have also been occasions when the Moon appeared to have green hues. Scientists say that such change in the Moon’s color occurred due to eruption of an Indonesian volcano called Krakatoa. It is said that the volcano’s explosion was as powerful as that of a 100 megaton nuclear bomb. Such explosions can be heard even by people located 400 miles away from the explosion site. The volcanic ash covering the sky resulted in change in the Moon’s color.