Lunar Eclipse

Eclipse means hiding. So when the Moon is hiding from Earth, it is Lunar Eclipse.

* Moon appears in the same location about 50 minutes later each night
** Moon image size can be calculated for any camera lens by dividing its focal length by 109.

Lunar Eclipse

Vice versa a lunar eclipse always occurs on Full Moon and when the earth comes in between the Sun and the Moon. Moon revolves around the earth in 29.5 days, and this duration is called a month. The "month" word is derived from the 29.5 day period. 

Why do we not have the lunar eclipse every Full Moon? In fact the Moon's orbit is 5 degree tilted from the orbit of the earth around the Sun. This means that Moon spends its most of the time either above or below of the earth orbit plane. To have a lunar eclipse, plane of earth's orbit around the Sun is important, because earth's shadows lie exactly in the same plane. During the Full Moon day, it passes either above or the below the earth's shadows so it misses them entirely. But 2-4 times each year, the Moon passes through some portion of the earth's shadows, and a lunar eclipse occurs. It may be Penumbral (this is for academic interest only and they are 35% of all the lunar eclipses and are difficult to see), partial or total.

When a lunar eclipse occurs, everyone who is on the night side of the earth can see it. During the total lunar eclipse, the earth blocks the sunlight completely reaching to the Moon, but still some indirect sunlight manages to reach the Moon and illuminates it. This light is deep red or orange in color and is much dimmer than pure white sunlight. Earth's atmosphere also helps to reach there. The total eclipse is so interesting and beautiful to see because of this light only. If earth had no atmosphere, the Moon should have been totally black on this total eclipse day. The colors depend on the earth's atmosphere. If there is lots of dust in the atmosphere, the Moon should look dark.

An eclipse of the Moon can only take place at Full Moon, and only if the Moon passes through some portion of Earth's shadow. The shadow is actually composed of two cone-shaped parts, one nested inside the other. The outer shadow or penumbra is a zone where Earth blocks some (but not all) of the Sun's rays. In contrast, the inner shadow or umbra is a region where Earth blocks all direct sunlight from reaching the Moon.

If only part of the Moon passes through the umbra, a partial eclipse is seen. However, if the entire Moon passes through the umbral shadow, then a total eclipse of the Moon occurs.
 

Unlike solar eclipses, lunar eclipses are safe to watch, you don't need even the telescope. Lunar eclipse photography is interesting. Go to these sites for more information - lunar eclipse photography,  Lunar Eclipse Gallery 1 and Lunar Eclipse Gallery 2.