A lunar eclipse occurs when the sun, moon, and Earth align so that Earth’s shadow falls across the moon’s surface. Monday night’s lunar eclipse is a total eclipse, which means Earth’s shadow will cover the moon completely.
The moon won’t be blacked out by our planet’s shadow. Instead, it will take on a reddish hue — anywhere from a bright copper to the brownish red of dried blood. Perhaps this is why we are seeing the term “blood moon” popping up all over the Internet. (For more on that, read Total lunar eclipse on April 14-15: What is a ‘blood moon’? )
The eclipse is visible from just about the entire continental United States, as well as Central America and parts of South America. If you live on the West Coast, you are especially lucky because you won’t even have to stay up too late to see it.
To watch the whole show from start to finish, your moon gazing should begin at 10:20 p.m. PDT, when the first faint shadow will start to fall on the moon. This is known as a penumbral eclipse, but be prepared — it’s subtle.
The show gets more interesting at 10:58 p.m., when the partial eclipse begins. It should look like a little bite was taken out of the moon. Continue to look up to see the Earth’s shadow move across the moon, covering more and more of its surface as the minutes pass.
By 12:07 a.m., the entirety of the lunar surface will be in Earth’s shadow. It will be glowing red, because even though our planet is blocking out direct light from the sun, the light of all the sunsets and sunrises on Earth still make it to the lunar surface.
Alan MacRobert of Sky and Telescope magazine explains it this way: “If you were standing on the moon during a total lunar eclipse you would see the Earth as a black disk with a brilliant orange ring around it. And this brilliant ring would be bright enough to dimly light up the lunar landscape.”
The moon will stay completely immersed in Earth’s shadow until 1:25 a.m.
If you are feeling heroic, you can keep watching the as the moon slowly moves out of our shadow until 3:10 a.m., when the eclipse event is over.
(Readers who are not on the West Coast may want to see Sky and Telescope’s handy chart on what to expect from this eclipse in a variety of time zones.)
The best way to see the show is to find an unobstructed view, get yourself a comfy chair and some warm clothes. And then, sit back and enjoy nature’s clockwork. It’s amazing!