why is the moon not red

The Moon is not red most of the time because it shines by reflecting sunlight directly, which appears white to our eyes. The Moon only appears red during a total lunar eclipse. This happens when the Earth comes between the Sun and the Moon, blocking direct sunlight from reaching the Moon. During a lunar eclipse, the Earth's atmosphere bends or refracts sunlight and filters out most of the blue light (shorter wavelengths) through a process called Rayleigh scattering, which is the same effect that makes sunsets and sunrises appear red or orange. The sunlight that passes through Earth's atmosphere and reaches the Moon is mostly red and orange light (longer wavelengths), giving the eclipsed Moon its characteristic reddish color. When the Moon is not eclipsed, it simply reflects the regular white sunlight and does not look red. Therefore, the Moon is generally not red because it is usually illuminated by direct sunlight, which is white. It becomes red only when illuminated by filtered sunlight during a total lunar eclipse caused by Earth's atmosphere filtering and bending light.