A lunar eclipse scheduled for Tuesday will be the first one to fall on the winter solstice in more than 300 years, according to NASA.
It will be visible to everyone in North America.
Astronomers say the phenomenon occurs when the moon travels through the shadow of the earth.
"The shadow of the earth is about eight times the size of the moon and if the moon happens in its orbit to pass through the earth's shadow, it goes dark," says Michel Fich, Astronomy Professor at University of Waterloo.
Lunar eclipses happen about two times a year, but the one on Tuesday will be one of a kind. December 21st is the winter solstice, which is the shortest day of the year. An eclipse hasn't fallen on the date since 1638, and will not happen again until 2094.
The eclipse will happen around 3:00 a.m. on Tuesday.
