A partial lunar eclipse lasting nearly four hours will be visible Friday evening, starting around 7:50 p.m. it will be visible in much of the Northeast.

Lunar eclipses occur when the sun, Earth, and moon are aligned, and the moon travels into the Earth’s shadow. Friday’s partial eclipse, the last of the year, will be harder to notice because the eclipse will be created by only the outer edge of the Earth’s shadow, called the penumbra.

Lunar eclipses, unlike solar eclipses, are safe to view with the naked eye and with binoculars.