Trending Now - Prepare for a Rare Blue Moon Event on May 31

WHO:

WGAL - The event involves the appearance of a Blue Moon.

Forbes - Astronomers define a Blue Moon as the third full moon in a row within a single astronomical season.

WHAT:

ABC News - The upcoming Blue Moon will be the most distant and smallest-looking full moon of the year, appearing at a distance of 252,360 miles (406,135 kilometers) from Earth.

ABC News - The Blue Moon will appear about 6% smaller and 10% dimmer than an average full moon, according to Gianluca Masi from the Virtual Telescope Project.

ABC News - The brilliant star Antares will be visible alongside the Blue Moon, temporarily disappearing for stargazers in regions such as Argentina, Chile, New Zealand, and eastern Australia as the moon passes in front of it.

ABC News - The upcoming Blue Moon will be the most distant and smallest-looking full moon of the year, appearing at a distance of 252,360 miles (406,135 kilometers) from Earth.

ABC News - The Blue Moon will appear about 6% smaller and 10% dimmer than an average full moon, according to Gianluca Masi from the Virtual Telescope Project.

WGAL - A Blue Moon will appear on Sunday, May 31.

Forbes - The Blue Moon is the second full moon in a single calendar month, occurring due to the mismatch between the moon’s 29.5-day cycle and calendar months.

Forbes - The first full moon of the month was the Flower Moon, which rose on May 1.

Forbes - The next monthly Blue Moon will occur on December 31, 2028, and a seasonal Blue Moon will occur on May 20, 2027.

WHERE:

Forbes - The Blue Moon will be best seen at moonrise on the eastern horizon.

WHEN:

WGAL - The Blue Moon will occur on Sunday, May 31.

Forbes - The best time to see the Blue Moon will be during dusk on Saturday, May 30.

WHY:

Forbes - The term "Blue Moon" refers to the rarity of the event, as full moons occur approximately every 29.5 days.

HOW:

ABC News - The Blue Moon will be best viewed at moonrise on May 30, glowing orange due to Rayleigh scattering as it rises in the eastern horizon.

WGAL - The moon may appear bluish in rare cases due to atmospheric particles scattering light.

Forbes - The Blue Moon will appear orange when it rises due to Rayleigh scattering, which affects how light passes through Earth's atmosphere.

(UPDATED May 28, 2026 16:19 UTC)

The upcoming Blue Moon, set to rise on May 30, will be the most distant and smallest-looking full moon of the year, appearing at a distance of 252,360 miles from Earth. According to Gianluca Masi from the Virtual Telescope Project, this Blue Moon will look about 6% smaller and 10% dimmer than an average full moon, and it will be accompanied by the brilliant star Antares, which may temporarily disappear from view in places like Argentina, Chile, New Zealand, and eastern Australia as the moon passes in front of it. Stargazers will have the best chance to see the moon at moonrise, when it will glow orange due to Rayleigh scattering as it rises on the eastern horizon.

(UPDATED May 28, 2026 14:15 UTC)

The upcoming Blue Moon, set to rise on May 30, will be the most distant and smallest-looking full moon of the year, appearing about 252,360 miles from Earth. According to Gianluca Masi from the Virtual Telescope Project, this Blue Moon will look about 6% smaller and 10% dimmer than an average full moon, and it will be accompanied by the brilliant star Antares, which may temporarily disappear for viewers in regions like Argentina, Chile, New Zealand, and eastern Australia as the moon passes in front of it. Stargazers will have the best view of this celestial event at moonrise, when the moon will glow orange due to Rayleigh scattering as it rises on the eastern horizon.

(UPDATED May 28, 2026 06:21 UTC)

A Blue Moon is set to appear on Sunday, May 31, marking the third full moon in a row within a single astronomical season. This rare event, which typically occurs due to the moon's 29.5-day cycle not aligning perfectly with calendar months, will be best viewed at moonrise on the eastern horizon, and it may appear orange as it rises due to atmospheric scattering. The next monthly Blue Moon will take place on December 31, 2028, while a seasonal Blue Moon is expected on May 20, 2027.