What exactly is a "blood moon," and what's its connection to a lunar eclipse?

Skywatchers will find out on April 15, as the first total lunar eclipse of 2014 kicks off a series of four blood moons expected to grace the night sky over the next year and a half. Just check out the new NASA video above to learn more.

Total lunar eclipses are sometimes called "blood moons" as they can present "a dramatically colorful appearance, ranging from bright orange to blood red,” Fred Espenak, an astronomer with expertise in eclipses, told The Washington Post.

The dramatic colors are the result of dispersed light from the Earth's sunrises and sunsets falling on the face of the moon.

The upcoming eclipse will be the first in a lunar eclipse tetrad, the term for four consecutive lunar eclipses. It will begin at 2 a.m. EDT on April 15 and will be visible for most skywatchers in North America.

The first eclipse of the year is well placed for observers throughout the Western Hemisphere.

Unlike solar eclipses, lunar eclipses are safe to watch with the naked eye.