Micro Blue Moon marks year’s farthest full moon on Visakha Bucha
NARIT says the full moon on Sunday (May 31, 2026) will be slightly smaller than usual as both the year’s farthest and the month’s second full moon.
- A "Micro Blue Moon" will occur on Visakha Bucha Day, May 31, 2026.
- The "Micro Moon" aspect signifies it is the year's farthest full moon from Earth, causing it to appear slightly smaller than usual.
- It is also a "Blue Moon," which is the term for the second full moon in a single calendar month; the moon will not actually appear blue.
On the night of Visakha Bucha Day, Sunday (May 31, 2026), observers may watch for a “Micro Blue Moon”, the year’s farthest full moon and the second full moon of the month. The full moon will appear slightly smaller than usual and will not turn blue.
The full moon will appear slightly smaller than usual and will not turn blue.
The National Astronomical Research Institute of Thailand (NARIT) said that on Visakha Bucha Day 2026, which this year falls on Sunday, a “Micro Full Moon”, or the year’s farthest full moon, will occur at about 3pm, when the moon will be about 406,127 kilometres from Earth.
It will also be the second full moon of the month, or a “Blue Moon”.
Full moon to appear slightly smaller than usual
In astronomy, the two phenomena together are called a “Micro Blue Moon”.
The previous occurrence was about six years ago, on Saturday (October 31, 2020).
During the event, the full moon will appear slightly smaller than usual.
The moon orbits Earth in an ellipse, completing one orbit in about 27.3 days.
In any given month, there are times when the moon is closer to Earth and farther from Earth.
The point at which the moon is closest to Earth is called perigee, at an average distance of about 357,000 kilometres.
The point at which it is farthest from Earth is called apogee, at an average distance of about 406,000 kilometres.
If this coincides with the full moon phase, the phenomena in which the full moon is at its closest and farthest points from Earth in the year are called a “Super Full Moon” and a “Micro Full Moon”, respectively.
Second full moon of the month
A “Blue Moon” is the name given to the second full moon of a month.
It does not occur often, and the moon does not turn blue.
Two full moons occur in the same month about every 2.7 years on average because the lunar phase cycle takes about 29.5 days.
As a result, in some months with 31 days, two full moons can be seen.
Astronomers use the term “Blue Moon”, derived from the English expression “Once in a blue moon”, to describe such a phenomenon, referring figuratively to an event that is rare or happens only once in a long while.
The next phenomenon in which the full moon is at the year’s closest or farthest point from Earth and is also the second full moon of the month will be a “Super Blue Moon” on Friday (March 30, 2029).
