Overview
- The second full moon of May — a calendar “blue moon” — reached peak fullness at about 4:45 a.m. Eastern Time on May 31, 2026, a time confirmed by NASA and multiple astronomy outlets.
- This blue moon occurs near lunar apogee, at roughly 406,000 kilometers from Earth, making it a microluna that will appear a few percent smaller and less bright than an average full moon.
- Skywatchers across the Americas, Europe and Africa saw the fuller phase on the night of May 30, while observers in Australia, New Zealand and parts of Asia had the best view on May 31.
- The Moon will not actually be blue under normal conditions, though rare atmospheric particles from large volcanic eruptions or heavy wildfire smoke can tint the Moon bluish on occasion.
- The phenomenon is a calendar quirk of the 29.5‑day lunar cycle that happens every two to three years, and public outreach groups including NASA and astronomy projects offered simple viewing tips and live streams for anyone without a telescope.