Lunar Eclipse

Diagram of a lunar eclipse: Earth's shadow covered the moon
Lunar eclipse occurs when part or whole cross-section covered by the shadow of the moon earth

Lunar eclipse occurs when part or the whole cross-section covered by the shadow of the moon the earth. That happens when the earth is between the sun and the moon on a same straight line, so that sunlight can not reach the moon because it is blocked by the earth.
another explanation, a lunar eclipse when the moon appeared was in opposition with the sun. But because the slope of the field of the moon's orbit to the plane of Ecliptic, it is not any opposition in the sun will result in a lunar eclipse. The intersection of the orbit of the moon with the Ecliptic field will bring up the point of intersection 2 pieces called nodes, that is the point where the moon cut Ecliptic field. This lunar eclipse will occur when the moon is in opposition to the node. The moon takes 29.53 days to move from one point of opposition to the other opposition point. It should, if there is a lunar eclipse, will be followed by a solar eclipse because the two nodes are located on the line connecting the sun to the earth.
In fact, on the occasion of lunar eclipse, the moon is often still visible. This is because there still exists a deflected sunlight to the moon by the earth's atmosphere. And most of the deflected beam has a red light spectrum. That is why at the time of a lunar eclipse, the moon will appear dark red can be copper, orange, or brown.
Lunar eclipse can be observed with the naked eye and is not dangerous at all.

The types of lunar eclipse
  • Eclipse-month total  --  At this eclipse, the moon will be right in the umbra region.
  • Eclipse the moon partially  --  At this eclipse, not all parts of the moon is blocked from the sun by the earth. While most other lunar. surface in the penumbra region. So that there is still some sunlight reaching the surface of the moon.
  • Eclipse moon penumbra  --   At this eclipse, all parts of the moon was in the penumbra. So that the moon can still be seen with the bleak colors.