Rising Moon Illusion
June 29, 2007
Did you ever notice how large the full Moon looks on the horizon and how small it looks overhead? It’s an illusion, called the Moon Illusion. This time exposure of the full Moon rising shows that the size of the Moon remains the same as it ascends, and is no larger near the horizon than it is well above it. The Moon Illusion is the result of the way the brain processes visual information into a spatial reference frame. While there are many explanations of the Moon Illusion, none of them are universally accepted.