Fred Espenak Lists May 1 Flower Moon Full Moon as Micromoon
Fred Espenak’s AstroPixels website lists the May 1, 2026 flower moon full moon as a micromoon, putting it among 2026’s closest-label debates. Timeanddate.com does not count that moon, leaving the year with two or three full micromoons depending on which source a reader uses.
Espenak’s Micromoon Rule
Espenak defines a micromoon as a new moon or full moon phase near apogee, within 90% of the moon’s greatest distance from Earth in a given orbit. He wrote, “In contrast to the supermoon there is the micromoon. When either the new moon or full moon phase occurs near apogee (within 90% of its greatest distance to Earth in a given orbit), the moon subtends its smallest apparent diameter as seen from Earth. This phenomenon, referred to a apogee syzygy or apogee new/full moon, is popularly known as a micromoon. Using the definition above and applying it to the moon’s mean apogee and perigee distances results in a mean limiting distance of 401,293 km for a micromoon.”
The distinction turns on distance and on how each source draws the cutoff. The moon’s orbit is not a perfect circle, and it has a nearest point, perigee, and a farthest point, apogee, each month. Under Espenak’s rule, the full moon around apogee becomes a full micromoon.
May 1 and May 31, 2026
AstroPixels lists three full micromoons in 2026: May 1, May 31 and June 29. Timeanddate.com lists just two full micromoons for the year, May 31 and June 29. That leaves May 1 as the dividing line between the two counts.
Both sources list the full Strawberry Moon of June 29, 2026 as a micromoon. They also list the Blue Moon of May 30-31, 2026 as a micromoon, and the article says that full moon will be 252,360 miles, or 406,135 kilometers, from Earth. The moon’s average distance is 238,900 miles, or 384,472 kilometers.
December 9, 2026
One new micromoon appears in 2026: the new moon on December 9. Espenak lists that event at 251,460 miles, or 404,687 kilometers, from Earth. That gives the year a split result: two full micromoons by one source, three by another, and one new micromoon either way.
For readers tracking the 2026 lunar calendar, the practical takeaway is simple. The May 1 Flower Moon is the disputed entry, while May 31 and June 29 appear on both lists. The count changes only because the definition of “near apogee” changes.
