ECLIPSE

an astronomical event that simply cast the shadow by one body upon another, when it passes in front of a source of light.

eclipses, both solar and lunar, are a result of the movements of the Sun, Moon, and Earth.

Sun - is the centre of our solar system, and by far the dominant object in it.

Moon -  is fairly unremarkable, except for its size; it is one of the larger moons in the solar system.

Earth - is the third planet out from the Sun.

The Earth and Moon

This is how our Earth and Moon relate to each other, and to the Sun; and it is the motions shown in this diagram that cause eclipses.

Two Categories of Eclipse:

Solar eclipse (Eclipse of the Sun)

- occurs when the Moon passes between the Earth and Sun.

- the Moon blocks the light of the Sun and a shadow of the Moon is cast on the

Earth’s surface.

- this happens at the New Moon.

Lunar eclipse (Eclipse of the Moon)

- occurs when the Earth passes between the Moon and Sun.

- the Earth throws a dark shadow across the Moon.

- this happens at the Full Moon.

Three Types of Solar Eclipse:

1)  Total solar eclipse is when the Sun is completely covered by the Moon.

2) Partial solar eclipse is when the Moon covers only part of the Sun, taking a "bite" out of it.

3)  Annular eclipse occurs when the Moon covers the centre of the Sun, but not its edges, leaving a ring (or annulus) of the Sun visible around its edges.

Total Solar Eclipse

Here, the moon passes between the Earth and Sun at a point in its elliptical orbit when it is relatively close to the Earth. As it does so, it casts a shadow. The umbral part of the shadow (the umbra) is the area where the Sun is totally obscured by the Moon. During a total eclipse, the Moon is close enough to the Earth that part of the umbra falls upon the Earth.

Partial Solar Eclipse

There is an area, outside the umbra, where the Sun is only partly covered by the Moon; this is known as the penumbra, and it covers a much larger area of the Earth than the umbra.  Looking at the tip of the penumbra pointer, notice that it can "see" the top part of the Sun, but not the bottom part;

Annular Solar Eclipse

Here, the Moon in its elliptical orbit is farther from the Earth, and the umbra is too short to reach the Earth. However, the Moon is directly in front of the Sun, so the parts of the Earth underneath it see a partial eclipse where the centre of the Sun, rather than a "bite" at the side, is covered. This leaves a ring -- an annulus -- of the Sun visible round the edges of the Moon.

Three Types of Lunar Eclipse:

1) Penumbral eclipse, the Full Moon enters the Earth's penumbral shadow. The light from the Earth is partially blocked, and the Moon grows dimmer.

2) Partial lunar eclipse, part of the Moon is within the Earth's umbral shadow. From the Earth, we see the Moon partially in shadow, almost as if it wasn't full.

3) Total lunar eclipse is when the Moon is completely shadowed by the Earth. The Moon passes through the Earth's umbra, and no direct light can reach it from the Sun. 

Penumbral Eclipse

A penumbral eclipse can be a partial penumbral eclipse or a total penumbral eclipse, where the entire Moon is in the penumbra; however, most penumbral eclipses are partial, since the penumbral shadow of the Earth is only about as wide as the Moon, so it's rare for the Moon to fit entirely within the penumbra without entering the umbra (and hence making a partial umbral eclipse). 

Partial Lunar Eclipse

In the later stages of a partial eclipse, as the Moon darkens, red coloration may become visible on the shadowed side of the Moon. 

Total Lunar Eclipse

 The Earth's atmosphere refracts -- or bends - light, at the same time filtering it, so that it illuminates the Moon with a dark red colour. Depending on the prevailing condition of the Earth's atmosphere, in terms of cloud cover and dust from volcanic eruptions, the actual colour of the Moon at totality can vary from near black (particularly at mid-totality), to rust, brick red, or bright copper-red or even orange. 

Watch Me!

References

http://starchild.gsfc.nasa.gov/docs/StarChild/questions/question6.html

http://www.hermit.org/eclipse/why.html

http://www.youtube.com/watch?v=_hasUZ3SFCw

http://www.videojug.com/film/what-is-an-eclipse