Rare Blue Microluna and Antares Alignment Visible on May 31, 2026

On 31 May 2026 a rare astronomical event will occur when a second full moon in the month coincides with the Moon’s apogee, creating what astronomers call a “blue microluna.” At its most distant point from Earth, the Moon will appear up to 14 % smaller than a super‑moon and about 6 % smaller than an average full moon.

The phenomenon will be best observed from the Southern Hemisphere, with clear views expected in Argentina, Chile, New Zealand, eastern Australia, parts of Antarctica and other southern locations. As the Moon passes in front of the bright red super‑giant star Antares—known as the “heart of the Scorpion”—the star will be briefly hidden.

Although termed “blue,” the Moon will not change colour; the name only reflects the rarity of two full moons in one calendar month. Jan Carlo Mazi of the Virtual Telescope Project noted the microluna will look about 6 % smaller and 10 % fainter than a typical full moon, offering a unique glimpse of lunar dynamics and planetary motion.