A rare blue micromoon will appear this weekend, combining a second full moon in one month with the year’s most distant and smallest-looking full moon. The first full moon of May occurred on May 1. Because the moon’s orbit is elliptical, Sunday’s full moon will be 252,360 miles from Earth, making it appear roughly 6 percent smaller and 10 percent dimmer than average. The difference is expected to be subtle for most viewers. The bright star Antares will lie close to the moon and may be briefly hidden by it for observers in parts of the southern Pacific, including Argentina, Chile, New Zealand, eastern Australia and sections of Antarctica. Elsewhere the star will remain visible beside the moon. The term blue moon refers only to the timing of two full moons in a single month and does not describe color.
