There’s a Blood Moon on the rise, and people around the world will be able to catch a glimpse of it on Friday July 27th, 2018, when the Moon ducks into the Earth’s shadow. North America, however, is going to miss it — so we’ll have to catch the event on a live stream.
This will be the second Blood Moon (also known as a lunar eclipse) of the year. And it’ll last a whopping one hour and 43 minutes, making it the longest one this century. But the eclipse’s impressive length also means that the Moon itself will actually look a little smaller and dimmer than usual.
That’s because the Moon will be as far away as it gets from the Earth on its elliptical orbit, making the Moon appear smaller. But, the Moon also moves more slowly when it’s that far away, according to Frederick Walter, a professor of physics and astronomy at Stony Brook University. That lets it linger for longer in the Earth’s shadow and stretches out the length of the eclipse.
Folks in regions like the Middle East and much of Europe will get a good view of the eclipse (you can check your region’s visibility with timeanddate.com’s location tool). They’ll see the Moon turn a rusty red — which is where lunar eclipses get their “Blood Moon” nickname. During an eclipse, sunlight has to filter through the Earth’s atmosphere before it can illuminate the Moon. “Blue light bends more than red light, so blue light actually gets scattered out,” Walter says. So the light that the atmosphere projects on the Moon is red, giving it that bloody glow.
For those of us in North America stuck watching the eclipse online, wewillget a bit of a consolation prize if we go out and look at the sky Friday night: a full Moon, and great view of Mars which will be directly opposite the Sun. It’s “a once-in-two-years treat called ‘Mars in opposition,’” Brian Resnick explains forVox. “That’s as bright as Mars gets,” Walter says.
Plus, there’s always next year. The Moon will pass through the Earth’s shadow again on January 21st, 2019. And yes, we should be able to spot it from North America.