A blood moon and total lunar eclipse are happening on Sunday. How to watch and what time they'll happen.

A lunar eclipse and a “blood moon” will occur on Sept. 7. Despite the dramatic name, a blood moon refers to the deep red hue the moon takes on when it passes through Earth’s shadow during a lunar eclipse, known as the eclipse’s totality point.

This weekend’s celestial event will be visible to an estimated 85% of the world’s population — although no one in the Americas will be able to see it. Lunar eclipses only happen twice a year on average — the upcoming one is the second and final of 2025, and the next is expected to occur on March 3, 2026, according to NASA.

Here’s what to know about Sunday’s upcoming eclipse.

What is a lunar eclipse?

A lunar eclipse happens when the Earth, the moon and the sun are perfectly aligned in orbit, but the Earth is positioned between the moon and the sun. Earth’s shadow blocks the sunlight from reaching the moon’s surface, causing it to dim, according to NASA. (In contrast, a solar eclipse happens when the alignment is similar, but the moon blocks the sun’s light from reaching Earth, NASA explains.)

Lunar eclipses occur when the moon is at its full moon phase — when the moon’s face is fully visible from Earth. Even though the moon enters its full moon phase every month, an eclipse only happens when the moon is inclined at a certain angle when its orbital path crosses Earth’s, according to Time and Date, a site that tracks astronomy and time zones.

What is a blood moon?

The moon takes on this particular shade of red because the only sunlight that reaches its surface comes from the edges of the Earth. Air molecules in the Earth’s atmosphere “scatter out most of the blue light,” NASA explains, which means the “remaining light reflects onto the Moon’s surface with a red glow.”

When and where can viewers watch the eclipse?

The lunar eclipse will start at 11:28 a.m. ET, and totality will happen at 1:30 p.m. ET, according to Space.com. The eclipse is expected to last roughly five hours and 27 minutes, while the blood moon will be visible for 82 minutes during that time, Time and Date said.

The entire eclipse will be visible to people in Australia, Asia, Africa and Eastern Europe; while stargazers in parts of Western Europe, such as the U.K. and Spain, and the easternmost parts of Brazil will catch some glimpses, but not the full eclipse, Space.com reported.

People in the Americas will not be able to see anything because the moon will be below the horizon and on the opposite side of the Earth during that time, Space.com said.

There is no risk of damaging your eyes if you want to watch the total lunar eclipse, according to the National Weather Service (NWS). If you want a closer look, NWS recommends watching with a telescope or binoculars, but no special eye protection is necessary.