Ice Halos by Moonlight
Explanation: What color is the Moon? It depends on the night.
Outside of the Earth's atmosphere, the dark Moon, which shines by reflected sunlight, appears a magnificently brown-tinged gray.
Viewed from inside the Earth's atmosphere the moon can appear quite different.
The featured image highlights a collection of apparent colors of the full moon documented by one astrophotographer over 10 years from different locations across Italy.
A red or yellow colored moon usually indicates a moon seen near the horizon.
There, some of the blue light has been scattered away by a long path through the Earth's atmosphere, sometimes laden with fine dust.
A blue-colored moon is more rare and can indicate a moon seen through an atmosphere carrying larger dust particles.
What created the purple moon is unclear - it may be a combination of several effects.
The last image captures the total lunar eclipse of 2018 July - where the moon, in Earth's shadow, appeared a faint red - due to light refracted through air around the Earth.
Today there is not only another full moon but a total lunar eclipse visible to observers in North and South America - an occurrence that may lead to some unexpected lunar colorings.