Watch On
The second full moon of May, the ‘Blue Moon’, rises tonight, marking the smallest full moon of 2026.
You can watch the full moon live online thanks to a free livestream from astronomer Gianluca Masi and his Virtual Telescope Project in Manciano, Italy. The livestream begins at 9:30 p.m. EDT on May 30 (0130 GMT on May 31), and you can watch it live here on Space.com (via the video above) or directly on the Virtual Telescope Project’s WebTV or YouTube channel, weather permitting.
The livestream will also feature archival images of the moon above some of Rome’s most iconic monuments, according to the Virtual Telescope Project.
What is a Blue Moon?
A Blue Moon can mean one of two things, though neither definition has anything to do with the moon actually appearing blue. The original meaning, known as a seasonal Blue Moon, refers to the third full moon in a season with four full moons, according to NASA. A later interpretation, arising from a misunderstanding of the original definition, refers to the second full moon in a single calendar month. Over time, this monthly definition has become widely accepted alongside the seasonal one, according to Time and Date.
The Blue Moon this weekend is a monthly Blue Moon. Because the moon’s 29.5-day cycle (from new moon to new moon) does not perfectly match the calendar month, monthly Blue Moons occur roughly once every 2 and a half years, according to NASA.
Why is it the smallest full moon of the year?
This year’s May 31 full moon also happens to fall just 19 hours before the moon reaches apogee — the farthest point from Earth in its slightly elliptical orbit. Because of this timing, it will be the most distant full moon of 2026, making it appear slightly smaller and dimmer in the night sky than usual. It is also sometimes referred to as a “micromoon” — the opposite of a supermoon, when a full moon happens near perigee, the closest point to Earth in the moon’s orbit.
A micromoon can appear up to 14% smaller than a full supermoon and up to 7% smaller than an average full moon, according to Time and Date.
Editor’s Note: If you snap a photo of the moon and would like to share it with Space.com’s readers, send your photo(s), comments, and your name and location to spacephotos@space.com.
