Blue Moon to Appear on 31 October 2020, Next one to appear in Year 2050

After one full moon sighting on October 1, there would be another one on October 31. For the first time since World War II, people across the globe will be able to see the rare blue moon on October 31. Arvind Paranjpye, director of Nehru Planetarium informed that there are two full moons this October. The term ‘Blue Moon’ is used to indicate a second full moon in a month. However, it has nothing to do with the colour of the moon.

The first full moon occurred on October 1 and the second will occur on October 31 at 8.19 pm. The phrase ‘once in a blue moon’ is used very often which means a rare occurrence and it was first used in the early 16th century to indicate something absurd. This rare Blue Moon will grace the sky with pale grey and white but it will feature a spooky spectacle to cap off a month of glorious sky watching.

       What’s The Maths Behind The Blue Moon?

There is a bit of mathematics involved in this. “Duration of a lunar month is 29.531 days or 29 days, 12 hours, 44 minutes, and 38 seconds. Hence, in order to have two full moons in a month, the first full moon should be on the 1st or 2nd day of the month,” Paranjpaye explains. This extra time accumulates over the months. After about 30 months there will be one extra full moon in the year, Paranjpaye said.

The director of Nehru Planetarium, Delhi, N Rathnashree said this term is a calendrical term. “It is too uncommon to have a Blue Moon in a month of 30 days,” she further said. The last Blue Moon in a month with 30 days was on June 30, 2007, and the next Blue Moon will be on September 30, 2050, Paranjpaye said.

NASA explained in a blog that Blue Moon is a phenomenon where a full moon appears twice in a month. There is typically one full moon in a month as they occur after every 29 days. But, sometimes, the second full moon is also in attendance in the same month.