On 31 October 2020, a rare Blue Moon will appear in the sky, which will be visible in the night sky from around 8:19 pm.
A Blue Moon is a second full moon in a calendar month. October has two full Moons this year out of which the second moon is usually anointed as the Blue Moon.
This time the Blue Moon is coinciding with Halloween. The last time such a phenomenon was seen on Halloween was back in 1944. There was a blue moon on Halloween in 2001, but it was only visible in the Central and Pacific time zones and as per NASA the next Halloween Blue Moon will occur in the year 2039.
The first Full Moon of the month – known as a Harvest Moon – occurred on October 1.
October 1 saw a full moon and the next full moon falls on October 31, said Arvind Paranjpaye, director of Nehru Planetarium, Mumbai.
“When there are two full moons in a calendar month, the second full moon is called the Blue Moon,” he added.
This sort of second full moon occurs after every 30 months.
The duration of a lunar month is 29 days, 12 hours 44 minutes and 33 seconds. Therefore, to have two full moons in a month, the first full moon should take place on 1st or 2nd of the month, Paranjpaye explained.
It is not too common to have a Blue Moon in a month of 30 days. “The last Blue Moon in a month with 30 days was on June 30, 2007 and the next one will be on September 30, 2050,” Paranjpaye said.
There were also two Blue Moons in 2018. The first one was on January 31 and the second Blue Moon was on March 31. “This was because the preceding month February had only 28 days,” Paranjpaye said.
The next Blue Moon will appear on August 31, 2023, he added.
Interestingly, the appearance of the Blue Moon is seemingly not related to its colour as it is quite rare that a Blue-colour moon appears in all its glory. If at all it happens, it occurs due to the dust and smoke particles present in the Earth’s atmosphere in the sky.
(With Inputs From Mint)
Also Read | Assam Govt Issues Revised SOP For Reopening Of Schools & Colleges