If you were wondering What is a Blood Moon? A Blood Moon is sometimes used to describe a Total Lunar Eclipse. When the Earth casts its shadow on a Full Moon and eclipses it, the Moon may get a red glow.
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.
On Sunday, millions of people around the world will enjoy the sight of a “blood moon”, as a lunar eclipse combined with a “supermoon” combines to make our natural satellite appear red in colour.
Sunday will be the fourth appearance of a blood moon over the last two years, in what is known as a tetrad series. The last time was in 1982; the next will be in 2033.