On 22 August, the world witnessed a 'Blue Moon.' While the nomenclature 'Blue Moon' suggests that the Moon would sport a blue hue, in reality, the Moon's colour remains unchanged. The term 'Blue Moon' is used to describe a rare phenomenon in the Moon's cycle. There are several definitions of a 'Blue Moon', but according to the standard definition, the most recent one occurred on Sunday night. 

A Blue Moon is a lunar phenomenon. It occurs every 29.53 days in the full moon stage. The lunar year is just over 354 days long and it is divided into 12 cycles, similar to the Gregorian calendar. However, the lunar year is nearly 11 days shorter than the year we generally follow, which is based on the orbit time taken by the Earth around the Sun. This sometimes causes “extra” full moons. A Blue Moon is usually described as the third full moon in a four-full-moon astrological season. This occurred in 2021 on 22 August. The 2 solstices and 2 equinoxes (summer and winter) of the year mark the commencement and the completion of astronomical seasons. The June solstice was on June 21, 2021. The September solstice will be on September 22, 2021. 

last night's "blue moon"; full moon in aquarius (2021) pic.twitter.com/aJ0DozK541

Each astronomical season normally has three full moons, for a total of 12 in the lunar year. Given that we use the Gregorian calendar, most people find this description of a Blue Moon to be a little complicated. But there is a simpler approach.

A Blue Moon is used more frequently to refer to the second full moon in a calendar month. However, this is incorrect according to the Greenwich Observatory, which blames fake news spreaders. The phrase's origins are unknown, although the Observatory speculates that it could be a mispronunciation of "belew," which means "to betray," implying that the Moon deceives observers by arriving too early in the seasons.

Blue Moon - 23th August 2021 Tabriz - Iran pic.twitter.com/7gRGmMSPNO

The next time the event occurs will be on August 19, 2024. After that, it will be on May 20, 2027. According to the calendar month definition, the next Blue Moon will occur on August 31, 2023. After this, it will be followed by the next one on May 31, 2026, and December 31, 2028. Post that, the Blue Moon dates are:

The next Blue Moon, according to both parties' definitions, will not occur until 2037. That will also mark the next time there are two monthly Blue Moons in the same year. This is a rare coincidence and was last witnessed in 2018.

The Blue Moon🌕 In My Telescope 🔭 It’s so beautiful ✨🥰 pic.twitter.com/D36eFINfTn