Have you ever watched your shadow move around as you walk or made shadow puppets on the wall? Shadows are just dark areas created by something blocking a light source. If you walk in front of the sunlight, you cast a dark area or shadow on the ground on the side opposite the sun. If you put your hands in front of a flashlight in a dark room, you can create dark areas on the wall to make shadow puppets. On a much larger level, shadows can be created in outer space. Sometimes the light from the sun is blocked by our entire planet, which creates a giant shadow on the moon. We call this a lunar eclipse. Lunar is from Latin and refers to the moon. Eclipse is from Greek ekleipsis, meaning to fail to appear.