On 27 July 2018, there will be a longest total lunar eclipse , during which the moon appear a lot bigger and also red.And the eclipse can be seen for the whole one hour. So ,what causes the moon to turn red?.This question baffled scientists for many years , but with new technology, it has been discovered that the moon turns red , when the earth blocks the light coming from the sun to the moon , it casts two shadows called the penumbra and umbra shadow . ...