The Earth will pass between the Sun and the Moon in the early hours of November 19, casting a shadow on the latter. The eclipse will peak shortly after 4 a.m. ET, when our planet will block out 97 percent of the sun’s light, giving the moon a reddish hue.
According to NASA, the partial lunar eclipse will last 3 hours, 28 minutes, and 23 seconds — longer than any other eclipse between 2001 and 2100.
Here’s when and how to see the rare celestial event.
People in North America can watch the entire spectacle
Lunar eclipses are only visible in places where the moon is above the horizon.
Skywatchers in North America have the best seats in the house for the upcoming eclipse. The entire event can be viewed by people in all 50 US states, Canada, and Mexico.
You won’t need a telescope or binoculars; just go outside and look up at any time between 2:19 and 5:47 a.m. ET.
If you don’t want to brave the chilly morning air, you can watch the event live online here.
The most of of the eclipse will be visible in South America and Western Europe, though the moon will set before it ends. People in Western Asia and Oceania will miss the first part of the event because the moon has not yet risen. Those in Africa and the Middle East will miss out on the spectacle.
Don’t worry if you miss the eclipse. After this, NASA predicts 179 eclipses over the next eight decades, with an average of two per year. The next lunar eclipse will occur on May 16, 2022.
How a lunar eclipse works — and why it turns the moon red
Typically, the moon’s white-grey face is illuminated by sunlight reflecting off its surface. During a lunar eclipse, however, the Moon, Sun, and Earth briefly align so that our planet preventing sunlight from reaching the moon.
A total lunar eclipse occurs when 100 percent of the moon is obscured by the Earth’s cone-shaped shadow, known as the umbra. During a total or near-total eclipse, such as this month’s, the lunar surface takes on a bloody appearance.
That light show is thanks to oxygen and nitrogen particles in the Earth’s atmosphere. Because they are both better at scattering shorter wavelengths of light, such as blue or violet, colors with longer wavelengths, such as red, orange, or yellow, linger. As a result, when the Moon is in Earth’s shadow, those reddish colors dominate what you see.
READ MORE: Why Isn’t Our Moon a Planet?