“Blood Moon” – What You Need to Know About the Lunar Eclipse

The Moon moves from right to left, passing through penumbra and umbra, leaving in its wake an eclipse chart with times at different stages of the eclipse. Credit: NASA Science Visualization Studio

What is a lunar eclipse?

A lunar eclipse occurs when the Sun, Earth, and Moon align so that the Moon passes into Earth’s shadow. During a total lunar eclipse, the entire Moon falls into the darkest part of Earth’s shadow, called the umbra. When the Moon is in shadow, it takes on a reddish hue. Lunar eclipses are sometimes called “Blood Moons” because of this phenomenon.

Earth's atmosphere scatters sunlight during the lunar eclipse

During a lunar eclipse, the Earth’s atmosphere scatters sunlight. Blue light from the Sun scatters and longer wavelength red, orange and yellow light passes through, turning our Moon red. *Not to scale. Credit: NASA Goddard Space Flight Center/Science Visualization Studio

How to observe the eclipse?

You don’t need any special equipment to observe a lunar eclipse, although binoculars or a telescope will improve the view and the red color. A dark environment away from bright lights provides the best viewing conditions.

The eastern half of the United States and all of South America will have the opportunity to see all stages of the lunar eclipse. Totality will be visible across much of Africa, Western Europe, Central and South America, and most of North America.

May 2022 total lunar eclipse visibility map

A map showing where the lunar eclipse of May 15-16, 2022 is visible. The contours mark the edge of the visibility region at eclipse contact times. The map is centered on 63°52’W, the mid-eclipse sublunar longitude. Credit: NASA Goddard Space Flight Center/Science Visualization Studio

What if it’s cloudy or I’m not in the viewing area?

Nasa will feature a live stream of the eclipse from locations around the world! NASA will also host an episode of NASA Science Live, from 11 p.m. to 12 p.m. ET. Look here :

What can I expect to observe?

UTC (May 16) EDT (May 15-16) HAP (May 15) Milestone What is happening?
1:32 9:32 p.m., May 15 — Moon not yet visible The penumbral eclipse begins The Moon enters the penumbra of the Earth, the outer part of the shadow. The Moon is starting to darken, but the effect is quite subtle.
2:27 10:27 p.m. — Moon not yet visible The partial eclipse begins The Moon begins to enter the Earth’s shadow and the partial eclipse begins. To the naked eye, as the Moon moves through the shadows, it looks like a bite is being taken out of the lunar disk. The part of the Moon inside the shadow will appear very dark.
3:29 11:29 p.m. 8:29 p.m. The totality begins The entire Moon is now in Earth’s shadow. The Moon will turn copper red. Try binoculars or a telescope for a better view. If you want to take a photo, use a tripod camera with exposures of at least several seconds.
4:53 12:53 a.m., May 16 9:53 p.m. The whole ends When the Moon moves out of the Earth’s shadow, the red color fades. It will appear that a bite is taken on the opposite side of the lunar disc as before.
5:55 1h55 10:55 p.m. End of partial eclipse The entire Moon is in Earth’s twilight, but again the dimming is subtle.
6:50 2h50 11:50 p.m. End of penumbral eclipse The eclipse is over.

What else can I see tonight?

The Moon will be in the constellation Libra. Here are some other sky gazing tips for the month of May.

Why does the Moon turn red during a lunar eclipse?

The same phenomenon that makes our skies blue and our sunsets red causes the Moon to turn red during a lunar eclipse. This is called Rayleigh scattering. Light travels in waves and different colors of light have different physical properties. Blue light has a shorter wavelength and is more easily scattered by particles in Earth’s atmosphere than red light, which has a longer wavelength.

Red light, on the other hand, travels more directly through the atmosphere. When the Sun is above our heads, we see blue light all over the sky. But when the sun goes down, sunlight has to pass through more of the atmosphere and travel farther before reaching our eyes. Blue light from the Sun scatters and longer wavelength red, orange and yellow light passes through.

During a lunar eclipse, the Moon turns red because the only sunlight reaching the Moon passes through the Earth’s atmosphere. The more dust or clouds in Earth’s atmosphere during the eclipse, the redder the Moon will appear. It’s as if all the sunrises and sunsets in the world were projected onto the Moon.


Artist’s rendering of Earth during a lunar eclipse from the surface of the Moon. Seen from the Moon, as in this animation, the Earth hides the Sun. A red ring, the sum of all of Earth’s sunrises and sunsets, lines the Earth’s limb and casts a reddish light over the lunar landscape. With the darkness of the eclipse, the stars come out. The lights of cities in North and South America are visible from the night side of the Earth. The part of Earth visible in this animation is the part where the lunar eclipse can be seen. Credit: NASA Goddard Space Flight Center/Science Visualization Studio

Will a NASA spacecraft observe the eclipse?

NASA’s mission team for the Lunar Reconnaissance Orbiter (LRO), NASA’s spacecraft orbiting the Moon, will turn off the instruments during the eclipse. The spacecraft is powered by solar energy, so LRO will shut down to preserve its battery while the Moon is in shadow.

The Lucy spacecraft, currently traveling to study[{” attribute=””>Jupiter’s Trojan asteroids, will turn its gaze toward its home planet to observe a portion of the five-hour long eclipse – from just before the penumbral eclipse to just before the end of totality. The mission team plans to capture a view of both the Earth and the Moon with the high-resolution imager, L’LORRI. Since the spacecraft will be 64 million miles away and uses the Deep Space Network, it will likely take a few weeks to download and process the images.

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