October 1 saw a full moon and the next full moon falls on October 31. When there are two full moons in a calendar month, the second full moon is called the Blue Moon.
The Blue Moon on Oct. 31, 2020 will be the first full moon on Halloween in 76 years.
The usual monthly lunar phenomenon is that every month has one full moon and a new moon.
However, there are unusual occasions when the same month gets two full moons.
The last ‘blue moon’ in a month with 30 days was on June 30, 2007, and the next will be on September 30, 2050.
Arvind Paranjpaye, director of Nehru Planetarium, Mumbai said, “Duration of a lunar month is 29.531 days or 29 days, 12 hours, 44 minutes and 38 seconds. Therefore, to have two full moons in a month, the first full moon should take place on 1st or 2nd of the month,”
There were two Blue Moons in 2018. The first one was on January 31 and the second Blue Moon followed on March 31.
The next Blue Moon will be on August 31, 2023, Paranjpaye added.
Also Read | Centre stops Rs 1K Cr rural fund to Punjab
The blue in the ‘blue moon’ has nothing to do with color. It is an infrequent phenomenon involving appearance of an additional full moon within a given period.