Blue Moon phenomena refer to celestial phenomena that occur when there is an extra full moon within a period. It is proven that the moon colour does not change during this period, but only the bluish effect is seen on the moon due to atmospheric conditions and is referred to as blue a moon.
There are two categories of blue moon. One is a seasonal blue moon and the other is a monthly blue moon. A seasonal blue moon is considered to be as a real blue moon. It's at the third in all four moons that is present between each solstice and equinox. On the other side, the monthly moon is predicted from the Calender. There are 29.5 days between two full-fledged moon.
Both the blue moons are the sights to watch out for. A worth watching scene when these bodies appear in the sky and make it memorable for each watcher.
Blue Moon will be visible on October 31, 2020. Previously the moons were visible in 2018. The sight of two blue moons rarely occurs in a year. This time it's happening in 2020 and the next will be in 2037. Watchers have to wait till 2037 to see the next blue moon Halloween.