Barring thick cloud cover, virtually everyone in the Earth’s Western Hemisphere will soon have the opportunity to view a total lunar eclipse.

A lunar eclipse occurs when the Earth is between the sun and the moon, blocking the sun’s light that would normally shine upon the moon. As the moon moves farther into the Earth’s shadow, the moon will appear orange or red, thus the term “blood moon,” which is commonly used to describe the eerie look of the Earth’s closest celestial neighbor.

The eclipse begins Thursday night and continues into the wee hours of Friday morning. Starting shortly before midnight (EDT) Friday, the moon will move into the Earth’s shadow. The totality of the eclipse is set to occur between 2:26 a.m. and 3:31 a.m. Friday. The eclipse will end at or about 6 a.m., when the moon moves out of the Earth’s shadow and catches the full sunlight that it normally receives during a full moon.

Lunar eclipses always occur during a full moon. Solar eclipses — when the moon passes between the sun and the Earth — always occur during the dark of the moon, or, prior to the new moon.