Stargazers will witness a rare phenomenon, a second full moon in a month. It has been named as the “Blue Moon” that is not correct literally. The moon is not going to turn blue today, and the adage is to explain the rarity of the instance.

As the adage goes- Once in a blue moon means something rare and unusual. Unusual it is because normally every month has only one full moon day. However, this month is unique, and there will be two full moon nights. The first full moon occurred on July 2.

According to information released by the Planetary Society of India, the moon will reach its zenith at 4:13 p.m. itself. However, one can see the sight by looking eastwards when the moon will rise at 643 p.m. It will be different for different parts of India, but one can know it by looking at the local weather bulletins.

In one calendar year, one full moon is visible every month. Besides these 12 full lunar cycles, there are 11 extra days due to the difference between lunar and solar year. The extra days accumulate in two to three years and hence there will be an extra full moon once in two to three years. The last time when such a coincidence had occurred was in August 2012. The next episode will happen in January 2018.

NASA explained the phenomenon of colored moon and said that when the moon is very low on the horizon it appears red just like the sun that takes a golden hue during sunset. It is caused by the scattering of light by the aerosols in the atmosphere.

Aerosols that are shot up by volcanoes are very minute, and they disperse blue light and thus the myth of blue moon started.

According to a report by CNN, such an incidence happened in 1883 when Krakatoa – an Indonesian volcano erupted and triggered bright red sunsets and the moon to possess a bluish touch.