There have been rare cases where the moon literally appeared blue-ish. After major volcanic eruptions or large wildfires, smoke and ash particles in Earth’s atmosphere can scatter red light and allow more blue light to pass through. Following the 1883 eruption of Krakatoa, for example, observers around the world reported seeing blue-tinged moons.
What is a micromoon?
The second half of this month’s lunar pairing comes from the moon’s elliptical orbit around Earth. Because the moon does not travel in a perfect circle, its distance from Earth changes slightly throughout each orbit.
A micromoon occurs when a full moon coincides with apogee, the point at which the moon is farthest from Earth. By contrast, a full moon at perigee, the moon’s closest point to Earth in its orbit, is what’s known as a “supermoon.”
(The moon is even older than we thought.)
Given the extra distance, a micromoon appears smaller and dimmer compared to a “normal” full moon. The difference, however, is very subtle. Compared to a supermoon, a micromoon can appear roughly 10 to 15 percent smaller in apparent diameter. “Most casual observers wouldn’t notice the difference without a side-by-side comparison, but careful observers or photographers can detect it,” says McGowan.
