If you beat the crack of dawn on Election Day, there’s a stellar reason to step outside and look up at the skies in the hours before polls open: the last total lunar eclipse for more than two years.
Tuesday’s total lunar eclipse will last from 1 a.m. to 7 a.m. Tuesday. The moon will start to get red just after 2 a.m. and reach a maximum eclipse about two hours later at 3:59 a.m.
A lunar eclipse happens when the sun, the Earth and a full moon are all in alignment. The sun shines on the Earth, creating a shadow behind the Earth and making it possible for the moon to move through the Earth’s shadow, said Andrea Schweitzer, astronomer with the Little Thompson Observatory in Berthoud and physical sciences professor at Western Governors University.
The moon will start out white, become gray, and then transition to an orange-red. Because the moon is in the Earth’s shadow and not directly illuminated by the sun, the only light the moon sees is reddish light that first passed through Earth’s atmosphere.
The National Weather Service Forecast Office in Boulder forecasts clear viewing conditions in Denver. There may be a few clouds, but nothing blocking the moon, National Weather Service Meteorologist Zach Hiris said Friday. The forecast does not indicate any meaningful precipitation anywhere in the state, he added.
“All things considered, for an eclipse in November it certainly could be much worse weather to peek out and try to see it,” Hiris said.
The lunar eclipse is a global event. The red moon will be visible across North and Central America, as well as in Ecuador, Colombia, and western parts of Venezuela and Peru, during the totality phase, when the moon is completely in the Earth’s shadow, according to NASA. People in Asia, Australia and New Zealand will also be able to see the eclipse.
While the moon is eclipsed Tuesday, it will also be close to Mars and a red star called Antares. While this won’t necessarily affect the color of the moon, it is a “fortuitous placement” of three red things in the sky, said Jennifer Hoffman, interim director at the University of Denver’s Chamberlin Observatory.
“Celestial events like this help connect us to our solar system environment,” Hoffman said. “When you know the moon looks red because the sunlight hitting it has already passed through Earth’s atmosphere, it helps you feel a connection between the three celestial bodies.”
Ron Hranac, past president of Denver Astronomical Society and a member of the group’s board of directors, recommends people find a location to watch the lunar eclipse with a relatively unobstructed view to the southwest and west. You don’t have to find a dark sky location to see the eclipse, he said.
Because the Earth’s shadow is big in comparison to the moon, the lunar eclipse will last several hours. You don’t have to rush outside to catch it at a specific time, and you don’t need special equipment to see it, either.
“It’s something that people can look at with the naked eye. There’s no need for binoculars or a telescope,” said Hranac, a long-time amateur astronomer. “There’s no need for any special filters or eclipse glasses or anything else. Because you’re looking at the moon, you just step outside and enjoy the view.”
These reddish lunar events happen even less than once in a blue moon. You’ll get to vote on the next president well before the next total lunar eclipse comes in March 2025.