A Lunar Eclipse (Eclipse of the Moon) occurs when the Full Moon passes into the Earth's shadow.
The Moon is lit by sunlight. When that sunlight is cut off, the Moon should disappear. It does not vanish completely, however. The Earth has an atmosphere. Sunlight can bend around the atmosphere and reach the Moon. The thick atmosphere only lets red light pass. This causes the eclipsed Moon to appear a coppery red colour.
There are two types of lunar eclipses.
A total eclipse of the Moon can last for as long as 1 hour 43 minutes. During the partial phases, the Earth's shadow appears curved on the Moon. The ancient Greeks used this observation to postulate that the Earth was a sphere.
Lunar eclipses are less frequent that solar eclipses. There can be as few as NONE in a calendar year and as many as THREE. Unlike a solar eclipse, a lunar eclipse is visible over more than half the Earth. As long as the Full Moon is above the horizon, the eclipse is visible. The Full Moon is above the horizon on those parts of the Earth where it is night.
Although, lunar eclipse are less frequent than solar eclipse they are seen more often because, when they do occur, they are visible over a larger area.
