May 31 Blue Moon Brings 2026's Most Distant Full Micromoon, Looking 7% Smaller

9 articles · Updated · Time Out · May 20

May 31 will deliver South Africa’s second full moon of the month — a calendar Blue Moon — with moonrise around 5:40 p.m. to 5:50 p.m. SAST near sunset.
That full moon is also 2026’s most distant full micromoon, meaning it occurs near the Moon’s greatest distance from Earth and should appear about 7% smaller than an average full moon.
Blue Moon refers to timing, not color: it marks the second full moon in one calendar month after May 1’s Flower Moon, because the lunar cycle does not align neatly with the calendar.
A truly blue-looking moon is rare and usually requires volcanic ash or wildfire smoke to scatter red light; otherwise, the low moon’s oversized look near the horizon is an optical illusion.

A blue moon is just 12 days away, but will you actually be able to spot the difference in its size and brightness?

Beyond celestial cycles, what cataclysmic events on Earth can actually cause the moon to appear blue to the naked eye?

Are events like 'micro moons' genuine astronomical rarities or just popular labels for a barely perceptible change in our sky?