There have been rare cases where the moon literally appeared bluish. After large 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. After the eruption of Krakatoa in 1883, 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 with each orbit.
A micromoon occurs when the full moon coincides with apogee, the point at which the moon is farthest from Earth. In contrast, a full moon at perigee, the moon’s closest point to Earth in its orbit, is what is known as a “supermoon.”
(The moon is even older than we thought.)
Given the extra distance, a micromoon appears smaller and fainter compared to a “normal” full moon. The difference, however, is very subtle. Compared to a supermoon, a micromoon can appear about 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 spot it,” McGowan says.
