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Penumbral Lunar Eclipse. NASA Solar and Earth images, illustration by James Guilford.

A penumbral lunar eclipse occurs when the Moon passes through the thin outer shadow — penumbra — Earth casts out into space.

We’re fortunate that the night of July 4 is expected to be clear, and not just for the traditional booms and flashes of celebratory fireworks. Our Moon is getting in on the act, albeit with a much more subtle display in the form of a penumbral eclipse. The eclipse will take place from 11:07 PM to 1:52 AM EDT with maximum eclipse at 12:31 AM July 5.

We say subtle because, unlike a total lunar eclipse, Earth’s Moon will not change to reddish/coppery colors. The Moon will instead become oddly shadowed for a Full Moon, as it enters the outer fringes of Earth’s shadow in space — the penumbra. Only the “top” portion of Luna will pass through the penumbra making this eclipse especially slight. Still, it’s worth a look and it won’t be at a particularly late hour. A deeper penumbral lunar eclipse will take place the night of November 30, 2020.

Illustration of Earth's Umbra and Penumbra with Moon Positioned for Penumbral Eclipse.

Earth’s shadow streams into space away from the Sun. The shadow has a partially-shaded outer portion, and a deep inner cone. Moon is eclipsed when it enters Earth’s shadow. Moon is eclipsed when it passes through Earth’s shadow. Credit: SkySafari / J. Guilford

While it’s possible to view this eclipse with the unaided eye, binoculars will provide an enhanced view as would a small telescope.

Penumbral Shadow on Earth’s Moon at Maximum Eclipse. July 5, 2020 at 12:31 AM EDT. Simulation via SkySafari.

And just in case there’s any confusion, lunar eclipses are perfectly safe to view and photograph — it’s moonlight — so nothing to worry about there.

If you shoot any photos or have impressions to share with us, you can do so via our Twitter — @StephensObs

Penumbral Lunar Eclipse of July 4 – 5, 2020. Credit: NASA

NASA Eclipse Page available here: Penumbral Lunar Eclipse of July 4 – 5, 2020.