Light:
We need light to see. Light comes from different sources called light sources; our main natural light source is the sun. Other sources include fire, stars and man-made light sources such as light-bulbs and torches.
Thanks to light, we see life in glorious color: our eyes see different wavelengths of light as different colors.
Light appears to travel in straight lines, travelling from light sources until it hits the surface of an object.
Shadows are created when an opaque (non-see though) object blocks the light source. Shadows change depending on the distance the object is from the light source and the position of the light source.
What is an eclipse?
An eclipse occurs when one object in space blocks an observer from seeing another object in space. From Earth there are two main types of eclipses: solar eclipses and lunar eclipses.
Solar Eclipse
A solar eclipse occurs when the Moon passes in front of the Sun causing a shadow to fall on certain portions of the Earth. The eclipse is not seen from every place on Earth, but only from the locations where the shadow falls. From these locations, it appears as if the Sun has gone dark.
Lunar Eclipse
A lunar eclipse occurs when the Moon passes through the Earth's shadow. Lunar eclipses have the same three phases or types as solar eclipses including the umbra (total), ant umbra (annular), and penumbra (partial).
Lunar eclipses can be seen by a much larger area of the Earth than solar eclipses. They also can be viewed without special equipment to protect the eyes. Lunar eclipses are not totally dark. The Moon will reflect some sunlight that is refracted by the Earth's atmosphere. The light that is refracted is reddish in color and can cause the Moon to appear a dark brownish-red.