A "blue moon" does not actually look blue in color. It appears visually the same as any other full moon—typically white, yellow, grey, or sometimes orange or red depending on atmospheric conditions

. The term "blue moon" refers to a rare calendar event, such as the second full moon in a single calendar month or the third full moon in a season with four full moons, rather than the moon's color

. However, the moon can appear blue very rarely under special atmospheric conditions. This happens when the Earth's atmosphere contains particles of a very specific size (around 1 micron wide), such as after large volcanic eruptions or major wildfires. These particles scatter red light and allow blue light to pass through, giving the moon a bluish tint. Such an event occurred after the 1883 Krakatoa eruption, when the moon appeared bluish for several years

. In summary:

• Normally, a blue moon looks like a typical full moon, not blue in color

• A true blue-colored moon is extremely rare and caused by specific atmospheric particles scattering light

• Most "blue moons" people hear about are calendar-based definitions, not visual color changes

So, if you see a "blue moon," expect a normal-looking full moon unless unusual atmospheric events are present.