When does a Lunar eclipses happen?

Answer 1

A total lunar eclipse happens when the Earth blocks out the moon entirely from the sun.

Answer 2

Lunar eclipses generally occur twice a year, when the full moon passes directly into the shadow of the Earth. (Partial and penumbral eclipses happen when the Moon just misses passing into the Earth's shadow, or does so only partially.)

The NASA Eclipse Web Page will have a complete list of all eclipses between the years 2000 BC and 3000 AD.

http://eclipse.gsfc.nasa.gov/eclipse.html

Answer 3

A Lunar eclipse occurs when the Earth passes between the Sun and the Moon, causing the Earth's shadow to fall on the Moon. This usually happens when the Moon is full. Lunar eclipses can be seen from anywhere on the night side of the Earth where the Moon is above the horizon.