Tonight, for the first time in more than 30 years, a bright “supermoon” will fade to crimson during a total lunar eclipse. The event will last 1 hour and 11 minutes and, weather permitting, will be visible to North and South America, Europe, Africa, and parts of West Asia. Permission to “Aroo,” granted.
Bright as it may be, our moon doesn’t make its own light, but rather reflects the light it receives from the sun. From time to time, the moon gets swallowed up by Earth’s shadow as the planet passes between it, and our star.
To make matters even cooler, tonight’s eclipse not only coincides with a full moon, but also with a lunar perigee, the point at which the moon is closest to Earth along its 27.3-day orbit.
“That hasn’t happened since 1982, when The Clash was Rocking the Casbah, times were fast at Ridgemont High, and virtually no one knew what an Ewok was,” writes Jason Major, author of Lights in the Dark. If that wasn’t enough nostalgia for you, ’82 was also the year Sony released its first CD player, and Michael Jackson went full-blown Walking Dead. (Coincidence: we think not.)
Perigee and its opposite, apogee, occur because the moon’s orbit isn’t a perfect circle. Tonight, The Big Cheese will sit 31,000 miles closer to us than it does at its farthest point, making it appear 14 percent larger, and roughly 30 percent brighter in the night sky.
Then, there’s the whole “blood moon” thing: the eerie effect is simply the result of light passing through the Earth’s atmosphere. “As totality approaches, sunlight will reach the moon indirectly and be refracted around the ‘edges’ of Earth,”explains NASA. “Because of this, almost all colors except red will be ‘filtered’ out, and the eclipsed moon will appear reddish or dark brown.” It’s completely harmless, and will be more noticeable in locales with a high percentage of particles in the air, for example, where there have been recent forest fires. (We’re looking at you, PNW).
The Pale Blue Dot will cast its shadow beginning at 8:11 p.m. EDT, but the total eclipse won’t start until two-hours later. If you only have a minute to spare for this cosmic event, the eclipse’s peak will occur at 10:47 p.m. EDT. Should your viewing plans be hampered by pesky cloud cover, watch the NASA live feed here.
IMAGES: NASA Ames Research Center/Brian Day, Solar Happiness/YouTube