A rare blue micromoon will rise across much of the U.S. this weekend, appearing on May 31, 2026 [4].
This event is significant because it combines two distinct lunar phenomena. While a blue moon is the second full moon to occur within a single calendar month [1], a micromoon happens when the moon is at its apogee, the point in its orbit furthest from Earth [2].
Observers in various regions, including Middle Tennessee and Central California, will be able to see the event [3]. Because the moon is at its most distant point during this phase, it will appear as the smallest-looking full moon of the year [2].
The alignment occurs because the lunar cycle coincides so that the second full moon of May 2026 [1] also happens near the moon's apogee [1]. This specific combination of a blue moon and a micromoon is an uncommon astronomical occurrence [1].
There is conflicting data regarding when this specific combination will return. Some reports indicate a similar event will not occur until December 2028 [3], while other sources suggest it will not return until 2053 [3].
Skywatchers can expect a full moon that looks slightly smaller than average due to the distance from Earth. The event will be visible to the naked eye across most of the country, provided weather conditions remain clear [3].
“The moon will appear as the smallest-looking full moon of the year.”
The blue micromoon highlights the intersection of the lunar calendar and orbital mechanics. While 'blue moon' is a colloquial term for timing and 'micromoon' describes a physical distance, their simultaneous occurrence provides a rare visual contrast to the more common 'supermoon,' where the moon appears larger and brighter.
