A lunar eclipse is a wonderful thing to behold, and a magnificent sight. When there is a total eclipse, you get to see something that you will remember for the rest of your life. The sky is dark, and then the moon turns a reddish hue. Depending on atmospheric conditions on Earth, the Moon can be anything from a brownish color to a really dark red. While it is a breathtaking sight to behold, the question is why the Moon looks red during a total eclipse?
Interestingly enough, the fact that the Moon turns red during an eclipse was foretold in the Bible as a sign of the Apocalypse. However, this would seem to be a little odd, seeing as the Moon is eclipsed very often, and the world is still here. Fortunately today we know that the Moon turning red is not the forthcoming of the end of the world, and here is the reason why the Moon turns red during an eclipse.
Well, a lunar eclipse is when the Moon passes through one of the shadows of the Earth. Specifically, a total eclipse is when the Moon passes through the umbral shadow of the Earth. The sunlight is blocked by the Earth as the Moon crosses the shadow, and the light also has to pass through the atmosphere of the Earth.
As the light of the Sun passes through the atmosphere of the Earth, it gets refracted, and the light that reaches the Moon is very limited. This results in a filtering of the light that reaches the Moon, and therefore the blue light gets filtered out, and all that remains is the red light that we see during the eclipse. The light that reaches the Moon is also dimmer than the light that would reach the Moon because of the Earth being in the way.
Also, because the Earth has an atmosphere, the color of the Moon is effected by anything that might be going on during the time of the eclipse. For example, in 1992, the Moon appeared more of a brownish color because of the volcanic ash that was spewed from the eruption of Mt. Pinatubo. If the Earth had no atmosphere, the Moon would appear black during an eclipse, because there would be nothing to alter the color of the Moon, as observed from Earth.
So now you know why the Moon is red during a total lunar eclipse. it certainly is a sight to behold, and if you ever get the chance to see one, I suggest you do. It is a once in a lifetime experience, or possibly more if you are an astronomy buff, but it is certainly something you want to see in your life.
