On Tuesday, April 15, the moon will be eclipsed by the Earth's shadow. The 78-minute event will be viewable across the Western Hemisphere, according to NASA.
A total lunar eclipse occurs when the Earth, moon and sun are in perfect alignment and the moon is covered by the Earth's shadow. It glows in red. Two things make this lunar eclipse special for people in the United States: the location and the timing. The Western Hemisphere is facing the moon during the eclipse during the entire event, and it'll be nighttime in North America.
"Most [residents] of the continental United States will be able to see the whole thing," Noah Petro, Lunar Reconnaissance Orbiter deputy project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md., said on NASA.gov.
The Earth's shadow starts creeping across the moon at 2 a.m. Tuesday in Chicago, and will be at its height at 2:45 a.m. That's when the moon will be completely covered by the Earth's shadow, and turn red as the sun's rays are scattered. That's the blood moon.
A lunar eclipse gives the illusion the moon is changing phases in a matter of minutes.
The entire continent won't be able to witness a full lunar eclipse in its entirety again until 2019.