July’s full lunar eclipse is just around the corner, and the moon is set to make history in a few short weeks. As a special treat to stargazers, the full moon will also be a blood moon and will gift us with the longest total lunar eclipse of the 21st century.

When the moon passes through Earth’s shadow on July 27, it will create a total lunar eclipse that is set to last for 102 minutes. NASA maintains a list predicting lunar eclipses until 2100, and that time is pretty impressive compared to the shortest total lunar eclipse the agency lists there, which was in April 2015 and lasted just four minutes and 43 seconds.

lunar eclipse april 2014
An April 2014 total lunar eclipse.

What Is a Lunar Eclipse?

During a total lunar eclipse, the earth is situated between the sun and the moon, and the moon doesn’t receive direct sunlight.

A lunar eclipse only occurs at a full moon, and a total lunar eclipse can only happen if the sun, Earth, and moon are perfectly aligned.

Why Is It a Blood Moon?

The full moon appears with a red hue during a lunar eclipse because the only light anyone can see on it is refracted through earth’s atmosphere, instead of directly from the sun.

This colorful version of the moon is therefore sometimes referred to as a blood moon.

blood moon lunar eclipse
"Red sky at night, sailor's delight..."

Why Is This Lunar Eclipse So Special?

July’s lunar eclipse is particularly special because it’ll be the longest eclipse of this century. It will be partially visible for three hours and 55 minutes, but only fully so for about one hour and 43 minutes. July’s lunar eclipse is totally safe to watch without any special devices or equipment, unlike a solar eclipse.

In addition, Mars at opposition is also happening this year on July 27. Here on Earth, sky-gazers will have their closest view of Mars in 15 years.

How Do I Watch The Lunar Eclipse?

The eclipse will only be completely visible in Eastern Africa, the Middle East, and Central Asia, and partially seen in West Africa, South America, Europe, and Australia.

For those in North America, the Virtual Telescope Project is going to livestream the event, beginning at 2:30 p.m. Eastern on July 27.