Look up to the sky: October to end with Halloween Blue Moon
Blue Moon is usually the second full moon, wherein two full moon nights occur within a single month of the year.Updated: Oct 29, 2020, 17:05 IST
Halloween 2020, falling on October 31, has become extra special this year as the date also happens to be the occasion of the Blue Moon. It is a rare occurrence when there are two full moons in the same month. The popular phrase ‘once in every blue moon’ is attributed to this phenomenon because of its rare occurrence.
What is a blue moon?
According to the National Aeronautics and Space Administration’s (Nasa’s) Spaceplace website, a Blue Moon is usually marked as the second full moon, wherein two full moon nights occur within a single month of the year. The website also says that a Blue Moon comes only every two-and-a-half years with the next sighting to occur only on August 31, 2023.
Arvind Paranjpaye, director of the Nehru Planetarium in Mumbai, told the news agency PTI that two full moons occur in the same month on rare occasions. He also added that the full moon on October 31 will be called a Blue Moon after the month had another full moon earlier on October 1.
“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 the first or the second of the month” he said, according to PTI.
When did it happen last?
There was a Blue Moon in a month with 30 days on June 30, 2007, and September 30, 2050, would be the date for the next, according to Paranjpaye. Also, there were two Blue Moons on January 31 and March 31 in 2018.
Where can it be seen?
With the first and last dates of October 2020 being full moon nights, this phenomenon could be observed from all major countries of the world. According to a CNET report, the last Halloween full moon was on1944, during World War 2 and this time, it can be seen from all places on earth.
The Blue Moon myth
While largely confined to the Gregorian calendar system, the Blue Moon doesn’t denote the actual colour of the moon, rather to the second full moon night in a single calendar month.