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Lunar eclipse 2021 guide: When, where & how to see them

During a total lunar eclipse, the moon appears to turn red while passing through Earth's shadow.
During a total lunar eclipse, the moon appears to turn red while passing through Earth's shadow. (Image credit: NASA)

Two vibrant lunar eclipses will appear this year across Earth's skies. Weather permitting, people around much of the world will catch at least one of the lunar eclipses falling on May 26 and Nov. 19. 

The first lunar showstopper of 2021 will be a total lunar eclipse, when the face of the full moon temporarily transforms into a dark, reddish-brown orb. The second lunar eclipse of 2021 will be a partial eclipse, when the same copper color will spread over most of the moon's face, except for a tiny sliver. 

There's always a place on Earth where the sun don't shine. Our planet is perpetually casting a shadow into space, but the dark backdrop of the universe makes it impossible to notice unless an object — like the moon — dips itself partially or completely into the shadow. This murky region is shaped like a cone, and the rim of the cone's round cross-section — the penumbra — is a relatively light color, whereas this cone's core — the umbra — is a deeper red. Fortunately for skywatchers, the moon will immerse itself into this darkest part of Earth's shadow twice this year and will produce vibrant lunar eclipses. 

Related: Super Flower Blood Moon 2021: Where, when and how to see the supermoon lunar eclipse

The two parts of Earth's shadow create three possibilities for a lunar eclipse. The least noticeable kind are penumbral eclipses, in which the moon clips the faint outer edge of Earth's shadow for a slightly darker, silver color. This year's eclipses will be the more visually dramatic of the three types.

Earth's atmosphere bends sunlight, so the planet doesn't cast a jet-black shadow. If the whole moon passes through the innermost part of Earth's shadow, we see a copper-colored lunar face. This is known as a total lunar eclipse, or a "blood moon," and this exciting kind of lunar eclipse is what skywatchers will view on Wednesday, May 26, 2021. 

In 2021, we'll observe another umbra-touching lunar eclipse, on Friday, Nov. 19. With this eclipse, the moon will only partially pass through Earth's deepest shadow region. Take special notice of this eclipse if it shines in your skies: November's lunar eclipse will last longer than any other partial lunar eclipse this century, according to predictions by Fred Espenak at NASA's Goddard Space Flight Center. 

Total Lunar Eclipse on May 25-26

Map of a total lunar eclipse on May 26, 2021.  (Image credit: NASA's Scientific Visualization Studio)

The first lunar eclipse of the year will be a show-stopping blood moon. This total lunar eclipse will be visible in parts of Asia, Australia, the Pacific and the western Americas, according to Espenak. Some people are also calling this a supermoon because the lunar disc will appear 7% larger than average due to the moon's slightly closer proximity to Earth in its orbit during this month's full moon. 

The moon will undergo its deepest entry into Earth's umbral shadow for several minutes during early morning local time in the western parts of the United States. Countries along the Pacific Ocean's edge, from Alaska all the way down Mexico and to the ends of South America, can view most of the total lunar eclipse at similar times of night, too.

The eclipse technically begins Wednesday (May 26) at 4:47 a.m. EDT (1:47 a.m. PDT;; 0847 GMT). However, most viewers won't be able to tell the event is underway until the moon enters the umbra, at 5:44 a.m. EDT (2:44 a.m. PDT; 0944 GMT). At this point, the moon will get increasingly coated by the copper-color shadow until it is fully blanketed by the hue for 14 minutes, 30 seconds, beginning at 7:11 a.m. EDT (4:11 a.m. PDT; 1111 GMT). 

When the moon then slowly exits the umbra, the red filter on the lunar face will recede and the moon will regain a silvery color. The moon will have no more red parts at 8:52 a.m. EDT (5:52 a.m. PDT; 1252 GMT). The lunar eclipse officially ends at 9:49 a.m. EDT (6:49 a.m. PDT; 1349 GMT), when the moon fully exits out from all of Earth's cone shadow. 

The moon will have dipped below the horizon by the time the eclipse ends on the western coast of the United States. To find out whether you will be able to see this eclipse from your location, check out this interactive map from Time and Date.

This infographic shows the stages of the May 26, 2021 total lunar eclipse in Universal Time, or GMT. (Image credit: NASA's Scientific Visualization Studio)

In Honolulu, Hawaii, the total lunar eclipse will appear at more viewer-friendly hours and the full event will be visible from there: from start to stop, the eclipse lasts 5 hours, 2 minutes and 2 seconds. The moon enters Earth's shadow at 10:47 p.m. local time on Tuesday (May 25), starts displaying red colors at 11:44 p.m. local time, and reaches totality at 1:11 a.m. local time on May 26. 

The moon finishes displaying red at 1:25 a.m. local time, and it transitions into a darker-than-normal gray color caused by the penumbral phase until it fully exits the Earth's shadow at 3:49 a.m. local time. Time and Date is predicting showers for that night, however, so visibility is tentative.

In another part of the Pacific Rim, in Auckland, New Zealand, the penumbral phase of the lunar eclipse starts at 8:47 p.m. local time on Wednesday (May 26) and the first hints of red appear at 9:44 p.m. local time. The total lunar eclipse lasts from 11:11 p.m. to 11:25 p.m., and from then on the vibrant eclipse wanes back to the moon's normal appearance until the eclipse's end, at 1:49 a.m. on Thursday (May 27). Time and Date predicts some overcast viewing conditions for May 26, so clouds will perhaps add to the eclipse's already dramatic display in the sky and hopefully not obscure it.

The moon darkens when it enters into Earth's penumbra, the outer part of the planet's shadow in space. Total lunar eclipses begin and end with penumbral shadowing.  (Image credit: Stojan Stojanovski)

The dry weather of the American Southwest makes this region a good spot to watch the total lunar eclipse's highlights. Viewers in places like Albuquerque, New Mexico who wake up very early in the morning will be treated to the blood moon. The penumbral phase begins at 2:47 a.m. local time. The moon's face begins turning red at 3:44 a.m. local time, and then, just in time to go along with a very early breakfast, the moon will be completely red from 5:11 a.m. to 5:25 a.m. local time. The moon will remain partially red until shortly after 6 a.m. when the moon then sets below the horizon. 

If you cannot watch the eclipse in person, Time and Date will have a livestream of the eclipse beginning Wednesday at 5:30 a.m. EDT (0930 GMT). The Rome-based Virtual Telescope Project will also offer a live webcast of the eclipse through a collaboration with astrophotographers across Australia and the United States, beginning at 6 a.m. ET (1000 GMT). NASA will also host a virtual event on Tuesday where experts will talk about the "Super Flower Blood Moon." 

Related: Blood moon supercut! See the spectacular total lunar eclipse of 2019 in just 2 minutes 

Partial lunar eclipse on Nov. 18-19

A partial lunar eclipse rises over Stonehenge in the United Kingdom, on July 16, 2019. (Image credit: Jeff Overs/BBC/Getty)

The second and final lunar eclipse of 2021, on the night of Nov. 18-19, will be visible to all areas in the United States. Other parts of the world will get to see the eclipse too, such as the rest of North America, South America, islands in the Pacific Ocean and post of Asia. Parts of Europe like Ireland, the U.K. and Iceland can view the partial eclipse, but for a shorter period of time. 

During this partial lunar eclipse, most of the moon's face dips into the deep part of Earth's shadow. Since a tiny sliver of it does not reach that core shadow, the eclipse is categorized as partial. Most of the moon will turn a vibrant red color, so it won't be any less of a showstopper than May's eclipse. 

Most places in the U.S. will get to view the complete eclipse, which lasts 6 hours, 1 minute, 29 seconds, according to Espenak's predictions. The total eclipse viewing time can vary depending on an observer's location, so tools like this interactive map from Time and Date are helpful planning assets.

Map of the partial lunar eclipse of Nov. 19, 2021.  (Image credit: Fred Espenak/NASA)

According to the map, people in Chicago, Illinois may notice the moon getting darker at 12:02 a.m. local time on Nov. 19, when the moon first passes into the Earth's outer shadow. The moon will start turning red about an hour later, at 1:18 a.m. local time. The eclipse reaches its maximum at 3:02 a.m., and shows its final red colors at 4:47 a.m.; the whole event then ends at 6:03 a.m. local time. 

Hawaii will be treated to this lunar eclipse, too. The moon enters Earth's penumbral shadow at 8:02 p.m. local time on Nov. 18. The full moon will turn red beginning at 9:18 p.m., with the eclipse ending at 12:47 a.m. on Nov. 19. The moon will exit the penumbral shadow, wrapping up the lunar eclipse, at 2:03 a.m. local time. Viewers in Hawaii should keep in mind that this day of the year is cloudy 74% of the time, according to Time and Date. 

Viewers in western Europe can also catch brief moments of the eclipse if their day isn't cloudy. Skygazers in London can begin to see the red colors of the umbral shadow in the morning hours of Nov. 19, at 7:18 a.m. local time, but they'll only see this view if they find the moon low on the horizon. The moon sets below the horizon just minutes after turning red — at 7:24 a.m. local time — so European observers will have to be precise in their planning to catch hearty glimpses of November's lunar eclipse. 

Editor's note: If you capture an amazing photo of a lunar eclipse and would like to share it with Space.com for a story or gallery, send images and comments to managing editor Tariq Malik at spacephotos@space.com.

Follow Doris Elin Urrutia on Twitter @salazar_elin. Follow us on Twitter @Spacedotcom and on Facebook

Doris Elin Urrutia

Doris Elin Urrutia joined Space.com as an intern in the summer of 2017. She received a B.A. in Sociology and Communications at Fordham University in New York City. Her work was previously published in collaboration with London Mining Network. Her passion for geology and the cosmos started when she helped her sister build a model solar system in a Bronx library. Doris also likes learning new ways to prepare the basil sitting on her windowsill. Follow her on twitter at @salazar_elin.

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