July’s full moon is going to be a once-in-a-century beauty. Not only will it turn red as it passes through Earth’s shadow on Friday night, July 27 — this lunar eclipse will be the longest in a hundred years.
Partial eclipses before and after the total eclipse will last 1 hour and six minutes each, meaning the moon will spend 3 hours and 55 minutes behind at least a part of the Earth’s shadow.
Unfortunately for everyone in the United States, we won’t be able to see a single minute of the eclipse, total or partial.
This lunar show is reserved for the Eastern Hemisphere — places like Africa, the Middle East, Asia and Australia.
The best seats in the world will likely be in Madagascar and the Middle East, where the eclipse will occur right at midnight. East and west of those locations, people will have to look to the sky closer to moonrise or moonset, depending on which direction you’re traveling. Here’s where you can see the eclipse.
So what’s the reasoning for such a long eclipse time? A couple of things are at play here.
First, the moon is almost passing through the center of the Earth’s shadow.
Second, the moon is at its lunar apogee, or farthest point from Earth, which makes it appear that much smaller — think the opposite of a supermoon.
Both of these things combined are coming together near the end of July, making for the longest lunar eclipse between 2001 and 2100.
That last clarification needs to be made because the longest total lunar eclipse of the previous century was four minutes longer, and it happened almost 18 years ago to the day on July 16, 2000. That particular lunar eclipse was almost as close to the maximum time for a total lunar eclipse because the moon passed right through the bulls-eye of the Earth’s shadow.
The eclipse will be slightly north of the Earth’s shadow, but it’s close enough to be the longest eclipse for this century.
In a total lunar eclipse, the moon turns red — it’s often called a “blood moon” — for the same reason sunrise and sunset often have that rosy hue: the light illuminating the moon is filtered through the Earth’s atmosphere.
In addition to blood moons, there are also black moons and blue moons: