The century is relatively young yet, but the longest total lunar eclipse of the 21st centenary is set to go down on July 27. In fact, it's probably the longest such event between now and 2123, according to NASA's catalog of such things.
Aoccurs when the sun, earth and moon are in a line, casting the reddish-orange shadow of our planet onto the surface of the moon. This is why a total lunar eclipse is often referred to as a "blood moon."
The scientific explanation for the creepy, red-tinted satellite is admittedly a little less exciting than the more hysterical explanation from ancient times: that some kind of huge, unseen dragon in the sky is going to attempt to devour the moon but ultimately fail.
Whatever your favored explanation, it's happening this month and it will last for a whopping 1 hour and 43 minutes but there is a catch: it will only be visible in parts of South America, Africa, the Middle East and Asia. The map below from NASA provides an idea of where to plan your travel for the best blood moon viewing.
To figure out exactly when to watch for the total lunar eclipse where you are, you can plug your location into NASA's Lunar Eclipse Explorer for all the details.
If you can't catch this blood moon, don't worry. The next one comes in January and will be visible from Europe and the Americas.