This weekend’s blue moon also qualifies as a micromoon because it will occur near the moon’s farthest point from Earth in its orbit.
WASHINGTON — Skywatchers across the world will have a chance to witness a rare blue moon coinciding with a micromoon this weekend. Astronomers call the unique event a “blue micromoon.”
The full moon will peak early Sunday morning and marks the second full moon of the month, which is commonly referred to as a blue moon.
Why is it called a blue moon?
Despite the name, the moon will not actually appear blue. The term instead refers to the relatively uncommon occurrence of two full moons appearing within a single calendar month.
A blue moon occurs every two to three years when a second full moon squeezes into a single month. May 1 saw this month’s first full moon.
The upcoming full moon also qualifies as a micromoon because it will occur near the moon’s farthest point from Earth in its orbit. According to the Associated Press, the moon will be approximately 252,360 miles (406,135 kilometers) away from Earth, making it appear slightly smaller and dimmer than an average full moon.
Astronomers say the difference may be difficult for casual observers to notice.
“The differences are subtle enough to likely go unnoticed by most observers,” Gianluca Masi of the Virtual Telescope Project told the AP. Masi is hosting a live webcast of the event from Italy.
When is the next full moon?
The blue moon will reach peak illumination around 4:46 A.M. Eastern on Sunday, May 31, 2026.
A micromoon is the opposite of a supermoon, which occurs when a full moon is closer to Earth than normal and appears larger and brighter in the sky.
This weekend’s skywatching event also includes a bonus for astronomy enthusiasts. The bright red star Antares, often called the “heart of the scorpion” because of its position in the constellation Scorpius, will appear near the moon throughout the night.
Antares is a red supergiant star located roughly 550 light-years from Earth, according to NASA. One light-year equals nearly 6 trillion miles.
The Associated Press contributed to this report.