Rare ‘Blue Micromoon’ marks Visakha Bucha Day

The National Astronomical Research Institute of Thailand (NARIT) revealed that a rare “Blue Micromoon” will occur today on Visakha Bucha Day, with the full moon reaching its farthest point from Earth at around 3pm.

The phenomenon combines two lunar events: the year’s most distant full moon from Earth, known as a “Micro Full Moon”, and the second full moon of the same month, commonly called a “Blue Moon”.

NARIT said the Moon will be about 406,127 kilometres from Earth at its peak distance, making it the farthest full moon of the year. Since the event occurs during daytime, the exact moment will not be visible to most observers in Thailand.

However, the Moon can still be seen later in the evening, appearing slightly smaller than usual. The institute stressed that despite the name “Blue Moon”, the Moon will not actually appear blue. Suparerk Karuehanon, assistant director of NARIT, said the last “Blue Micromoon” occurred about six years ago on Oct 31, 2020.

When a full moon coincides with the Moon being nearest to Earth, it is called a “Super Full Moon”, while a full moon occurring at the Moon’s farthest point is known as a “Micro Full Moon”.

A “Blue Moon” refers to the second full moon in a single calendar month, a relatively rare event that occurs roughly every 2.7 years. Since the lunar phase cycle lasts about 29.5 days, some 31-day months can contain two full moons.

The term “Blue Moon” originates from the English expression “once in a blue moon”, referring to an event that happens only rarely. NARIT said the next combined event, known as a “Super Blue Moon”, is expected to occur on March 30, 2029. People interested in astronomy updates can follow NARIT’s official Facebook page for more information.