When Moon moves across some part of the shadow of the earth, then lunar eclipse arises. This can happen only when Sun, Moon and Earth are aligned closely, or very precisely, with the Earth in the mid. Therefore, there is for eternity full moon the night of the lunar eclipse. Its length and type depend upon the location of the moon comparative to its orbital nodes. And the next total lunar eclipse takes place on 15th June 2011, 21st December, 2010. And the next one eclipse of the Moon is the penumbral eclipse on 7th July, 2009.
The Earth’s shadow can be spitted into 2 individual parts: the penumbra and umbra. Surrounded by umbra, there isn’t straight solar radiation. On the other hand, on account of Sun's huge bony size, solar enlightenment is moderately blocked in an outer segment of the shadow of the Earth, which is identified the name penumbra.
When Moon moves across the penumbra of the Earth, then penumbral eclipse arises. The penumbra doesn’t have any reason for noticeable darkening of the surface of the Moon, although some may dispute that it turns a little yellow. And a different type of the penumbral eclipse is total penumbral eclipse, throughout which the Moon lies solely within Earth's penumbra. The Total penumbral eclipses are unusual, and when these happen, that section of Moon which is nearby to umbra can show somewhat gloomy than the rest of the Moon.
When a part of the Moon comes into the umbra then a partial lunar eclipse happens. When the moon moves wholly into the umbra of the Earth, one surveys the total lunar eclipse. And the Moon's speed all the way through shadow is almost one km. per second (2,300 mph), and entirety may last up to approximately 107 minutes. Particularly, when the Moon is close to its apogee, the furthest point from Earth in its orbit, its orbital pace is very slow. The diameter of umbra doesn’t reduce much with space. Therefore, a totally-eclipsed Moon happening near pinnacle will get longer the period of totality.
The Moon doesn’t entirely evaporate as it moves across the umbra owing to refraction of the sunlight through the atmosphere of the Earth into the shadow cone; whether the Earth had no environment, the moon would be entirely dark throughout an eclipse. And the red coloring occurs for the reason that sunlight reaching the Moon must navigate a dense and long layer of Earth's ambiance, at where it is dotted. Undersized wavelengths are more similar to be speckled through small elements, and so via the time the light has gone through the ambiance, the longer wavelengths take over.
This ensuing light we pick out as red. And this is the similar result that causes sunrises and sunsets to rotate the sky a glowing color; a substitute way of allowing for the trouble is to realize that, as viewed from Moon, the Sun would emerge to be setting (or rising) at the back of the Earth.
The subsequent scale was planned through André Danjon for ranking the overall dimness of lunar eclipses:
Each year there are generally at least two fractional lunar eclipses, even though total eclipses are considerably less common. Whether one knows time and date of an eclipse, then it is potential to forecast the happening of additional eclipses using an eclipse cycle like a Saros cycle. Nothing like a solar eclipse, which can simply be viewed from a convinced relatively undersize area of the world, and a lunar eclipse may be surveyed from anyplace on night side of the Earth.