This week’s “blood moon” will be the longest lunar eclipse of the century.
People in Africa and Asia will get the best views of the eclipse, and those in Europe, South America and Australia will see partial views, according to USA Today. The time of greatest eclipse will be at 4:21 p.m. Eastern time, and the total eclipse will last from 3:30 to 5:13 p.m. Eastern time, according to Space.com.
But there is some bad news: If you’re in North America, you won’t be able to see it yourself (but there will be live video online).
A total lunar eclipse happens when the moon and the sun are on opposite sides of the Earth, according to NASA. At that time, Earth blocks most of the sunlight that would usually hit the moon, so that much of the moon is in Earth’s shadow.
And the sunlight that does manage to pass through Earth’s atmosphere and reach the moon makes the moon look red — because most of the blue light has been filtered out by Earth’s atmosphere, NASA said.
This particular eclipse will be the longest because it’s happening at the same time the moon hits its apogee, which is the farthest point from Earth in the moon’s orbit, according to EarthSky. Since the moon will be at its most distant and smallest, it will take more time to cross the Earth’s shadow.
Stargazers may get to catch yet another treat — the day the eclipse happens is also the same day the planet Mars reaches its opposition, which means the planet will be opposite the sun and will appear bright, according to NASA. And on July 31, the Red Planet will be the closest to Earth that it’s been since 2003.
The longest total lunar eclipse of the 20th century happened on July 16, 2000, according to EarthSky. That eclipse lasted for 1 hour and 46.4 minutes.
Even if you’re in North America, you can still watch the July 27 eclipse online through the Virtual Telescope Project’s website, which will start livestreaming the eclipse at 2:30 p.m. Eastern time.
And if you’re bummed you’ll miss this eclipse, don’t be: North America will get views of the next lunar eclipse on Jan. 21, 2019 — and it “will especially favor viewers on the West Coast,” according to Space.com.