On Wednesday, January 31, the full moon will pass through the shadow of the Earth. For 77 minutes, the usually silvery moon will be covered with a blood-red/ochre shadow.
Even more notable: This total lunar eclipse will happen during the second full moon this month — a bonus event known as a “blue moon.” Such a coincidence (and it is nothing more than a coincidence) has not occurred in 150 years. Topping things off, this moon will be a “supermoon,” meaning it will appear slightly bigger and brighter than average.
It’s an impressive trifecta — but not everyone will be able to see the full show. Much of the East Coast of the United States will only see a partial lunar eclipse of the blue moon just before and during dawn. The best time to look for it is at 6:48 am ET (sunrise is at 7:15 am). Worse is that just before dawn, the moon will be near the horizon in the western sky. If you live in a wooded area, in a city, or anywhere with an obstructed view of the horizon, it will be hard to spot.
West Coasters will be able to see the full eclipse but will have to be up at 4:51 am PT to catch it. The Midwest has a shot too. In St. Louis, Missouri, people can check out the total eclipse just before sunrise, at 6:51 am CT. Alaska and Hawaii will have the best view in the United States. In Honolulu, the total eclipse begins at 2:51 am local time; in Anchorage, it begins at 3:51 am. (Check out TimeandDate.com to see when you might be able to catch a glimpse of the eclipse in your area.)
Much of South America, Africa, and Europe will, alas, be out of luck; the moon will have already set for the evening by the time it passes through the Earth’s shadow. (During a full moon, the moon sets when the sun rises, and vice versa.)
Why do we have lunar eclipses?
The simple answer is “because the moon sometimes passes through the shadow of the Earth.” But there’s more to it than that.
For one, it has to be a full moon. When the moon is full, it means the sun, Earth, and moon are in alignment, like so:
Now, you might be thinking: “Why don’t we have lunar eclipses every full moon?”
The moon’s orbit isn’t perfectly matched up with Earth’s. It’s tilted 5 degrees
No one is completely sure why — but it might have to do with how the moon was likely formed: from a massive object smashing into Earth.
This means during most full moons, the shadow misses the moon, as you can see in the diagram above.
There are two points in the moon’s orbit where the shadow can fall on the Earth. These are called nodes.
Everyone lucky enough to be on the night side of the Earth during a lunar eclipse is able to witness it. You don’t need any special equipment or protective glasses to view it (unlike the total solar eclipse). But a pair of binoculars will give you a better, more detailed view of the moon’s geography as it darkens in shadow.