When the moon passes between the Earth and the sun, it’s called a solar eclipse. When the Earth passes between the sun and the moon, it is a lunar eclipse.
The Earth casts its shadow far out into space, beyond the orbit of the moon. Once in a while the moon passes through the shadow, and an eclipse occurs.
When the Earth casts its shadow on a Full Moon and eclipses it, the Moon may get a red glow. Blood Moon is sometimes used to describe a Total Lunar Eclipse.
Total Lunar Eclipses are rare – only about one in three lunar eclipses are total. About four to five total eclipses can be seen at any place on Earth in a decade.
Every once in a while, four total lunar eclipses happen in a row. This is called a lunar tetrad. The total lunar eclipses happen 6 months apart. There are at least six full Moons between two total lunar eclipses in a tetrad.
The fourth and final lunar eclipse in an ongoing tetrad – four lunar eclipses in a row – happens on September 27-28, 2015.
syrabanu 