Topline
The so-called Blue Moon rose at dusk on Saturday, May 30, marking the second full moon of the month and completing a rare calendar quirk. May began with the full Flower Moon on May 1 and ended with this second full moon — something that happens only every two to three years because the moon’s 29.5-day cycle occasionally fits twice into a single calendar month. Here are all the best images of the Blue Moon from around the world.
Key Facts
The moon became full at 4:45 a.m. EDT on Sunday, March 31, but was best viewed at moonrise during dusk the preceding evening, on Saturday, March 30.
A monthly — the second full moon in a single calendar month — won’t happen again until Dec. 31, 2028. They occur roughly every 2.5 years.
The next astronomical highlight is a very close conjunction of two bright planets, Jupiter and Venus, in the post-sunset sky from June 9-11.
Why The ‘blue Moon’ Was Orange At Moonrise
For many observers, the blue moon didn’t look blue — it looked orange. That’s because when the moon is near the horizon, its light travels through a thicker layer of Earth’s atmosphere. Shorter wavelengths are scattered away, leaving warmer hues — orange as it appears, then yellow as it rises. At the same time, the moon illusion makes it appear larger when seen against foreground objects such as buildings, trees or distant hills. As the moon climbed higher, these effects faded, and it returned to its familiar pale white appearance.
Two Types Of ‘blue Moon’
Despite its name, a blue moon has nothing to do with color. The term most commonly refers to the second full moon in a single calendar month, as seen in May 2026. Because full moons occur roughly every 29.5 days, most months contain just one — but occasionally, timing allows for two. This kind of “monthly blue moon” occurs about every two to three years. The next one will take place on December 31, 2028 — a particularly rare case that will also coincide with a total lunar eclipse, also known as a Blue Moon. However, there’s a second definition — a seasonal Blue Moon, which is the third full moon in an astronomical season that contains four. The next of these will occur on May 20, 2027.
Why The ‘blue’ Moon Looked Small
This particular blue moon also came with an added distinction: it was the smallest full moon of 2026. Occurring close to apogee, the point in its orbit farthest from Earth, it appeared slightly smaller and dimmer than average — a so-called micromoon. The moon was roughly 50,000 kilometers farther from Earth than during a typical supermoon, reducing its apparent size and brightness.
What Causes A Full Moon
A full moon occurs when Earth moves directly between the sun and the moon, allowing sunlight to fully illuminate the side of the moon facing us. From our perspective, the lunar disk appears complete — a bright, round orb that rises at sunset and sets at sunrise. The moon does not generate its own light — it simply reflects sunlight — and is at all times half-lit by the sun, as Earth is. During the full moon phase, the illuminated half faces Earth, allowing us to see it fully lit.
Why We Only See One Side Of The Moon
We always see the same face of the moon because it is tidally locked to Earth. It rotates once on its axis in the same time it takes to orbit our planet — about 27.3 days — so one hemisphere permanently faces us. Although the moon orbits Earth in 27.3 days, the time between full moons is longer — about 29.5 days. That’s because Earth is also moving around the sun. After completing one orbit, the moon must travel a little farther to reach the same alignment with the sun and Earth again, creating the familiar cycle of lunar phases.