Eclipse occur because light cannot pass through opaque objects. When the Moon, Earth and the Sun are in line, there is an eclipse.
An eclipse occurs when one object gets in between you and another object and blocks your view. From Earth, we can experience two kinds of eclipses. An eclipse of the Moon and an eclipse of the Sun.
A eclipse of the moon is when, as the earth orbits the sun, it comes between the sun and the moon.When this happens the earth throws a dark shadow across the moon. This is known as an eclipse of the moon or a lunar eclipse.
An eclipse of the sun is if the moon passes between the Earth and the Sun. The Moon blocks the light of the Sun and a shadow of the Moon is cast on the Earth’s surface. This is an eclipse of the Sun or a solar eclipse.
During a solar eclipse, the Moon actually casts two shadows toward Earth. One shadow is called the umbra which becomes smaller as it reaches the Earth. This is the dark center of the Moon’s shadow. The second shadow is called the penumbra. This shadow becomes larger as it reaches the Earth. A total solar eclipse, or a complete blocking out of the Sun’s light, can only be seen by those who live in the area covered by the umbra. People who live in the area of the Earth covered by the penumbra will see a partial eclipse.
A total solar eclipse can only occur when two events happen at the same time. The first event is a new Moon. This phase of the Moon occurs when the Sun is almost directly behind the Moon, and we see only a sliver of the Sun’s light reflected by the Moon. During this time the Moon and the Sun appear close together. The second event that must occur is that the Moon must be in the right position, directly in the line of sight between the Earth and the Sun. These two events occur at the same time about once every year and a half.