Why is the moon still visible and red during a total lunar eclipse?
August 2, 2020 | Education
| During an eclipse, the moon receives light that has passed through and refracted by the atmosphere. The maximum angle of refraction for an observer on the Earth’s surface is about 0.5. Leaving the lower layers of the atmosphere into space, light is refracted by 0.5 again. Total about 1. And the diameter of the geometrical earth’s shadow at the moon is about 1.5. This means that the light refracted in the atmosphere falls into all areas of the geometric shadow near the surface of the Moon. The red rays of sunlight are less scattered and absorbed in the earth’s atmosphere than others; they mostly reach the moon through the earth’s atmosphere.
