Astronomy Essentials

A deep penumbral lunar eclipse overnight tonight

World map with large Eastern Hemisphere area in darkness and lighter areas to sides of it.
View full map. | Map showing the areas of visibility for tonight’s penumbral lunar eclipse. In a penumbral eclipse, the lighter outer part of Earth’s shadow falls on the moon. So this is a subtle kind of eclipse. You’ll need to look closely to notice it. Image via Dominic Ford from In-The-Sky.org. Used with permission.

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Penumbral lunar eclipse

People in eastern Europe, the Middle East, Africa, Asia, Australia, New Zealand, Antarctica, the South Atlantic Ocean, the Indian Ocean and the Pacific Ocean will see a deep penumbral lunar eclipse during the night of May 5-6, 2023.

Penumbral eclipse begins at 15:13 UTC on May 5. That is 11:13 a.m. EDT in North America, and the moon isn’t up at that time. That’s why this eclipse is not visible from the Americas.
Greatest eclipse is at 17:22 UTC on May 5 with a penumbral magnitude of 0.9655. In other words, at greatest eclipse, nearly all of the moon will be inside the Earth’s outer penumbral shadow. The moon will never go into Earth’s darker umbral shadow. So it will never seem as if a dark bite has been taken out of the moon. Instead, it’ll be a subtle darkened shading on the moon, and, at mid-eclipse, only a small sliver of the moon will fall outside this dark shading.
Penumbral eclipse ends at 19:31 UTC on May 5 (3:31 p.m. EDT).
Duration of eclipse: This is a deep penumbral lunar eclipse with a duration of 258 minutes.
Note: A penumbral lunar eclipse is the most subtle kind of lunar eclipse, one that most people won’t even notice. The moon’s shadow won’t be detected until the disk of the moon is immersed in about 2/3 of the penumbral shadow. Of course, this depends on the atmospheric conditions and a person’s visual acuity.

The full moon and eclipses

If this full moon were truly opposite the sun, there’d be a total umbral eclipse of the moon. That is, the darkest part of Earth’s shadow – the umbra – would cover the moon at mid-eclipse. But this full moon in May sweeps to the south of the Earth’s umbra. So no total or partial lunar eclipse in the Earth’s dark shadow can take place.

Instead, the full moon almost fully passes through the Earth’s penumbral shadow. So it’s a very deep penumbral eclipse. At no time will Earth’s dark shadow take a “bite” out of the moon. Instead, penumbral eclipses are all about subtle shadings.

Tonight’s penumbral lunar eclipse occurs when the moon is in the constellation of Libra the Scales.

Find the moon’s path with respect to Earth’s umbral and penumbral shadows below.

Diagram of moon passing through Earth's shadow and world map showing eclipse visibility.
A map for the penumbral lunar eclipse tonight. It sweeps across eastern Europe, Africa, Asia, Australia, New Zealand, Antarctica and Indonesia. Areas in white on the map will see the total penumbral eclipse. The line down the middle notes where greatest eclipse occurs. Shaded areas will see part of the eclipse and dark areas are where the eclipse is not visible. Note the difference between UTC and TDT (terrestrial dynamical time, often abbreviated TT as well). Lunar eclipse maps here. Image via Fred Espenak. Used with permission.

Visit Timeanddate.com to get an exact timing of the eclipse from your location.

Eclipses in 2023

Tonight’s penumbral lunar eclipse is preceded two weeks earlier by a hybrid solar eclipse on April 20, 2023. The fact is, these two eclipses take place within a single eclipse season.

An eclipse season is an approximate 35-day period during which it’s inevitable for at least two (and possibly three) eclipses to take place.

Then later this year, the October 2023 eclipse season will feature a annular solar eclipse on October 14, 2023, and a very shallow partial lunar eclipse on October 28, 2023.

Maps and data for the total lunar eclipse

Visit Timeanddate.com to get an exact timing of the eclipse from your location.

Penumbral lunar eclipse photos from our EarthSky community

Submit your photo to EarthSky here.

Five moon images showing sublte progress of penumbral lunar eclipse.
View at EarthSky Community Photos. | Soumyadeep Mukherjee of Kolkata, India, captured these images of the penumbral lunar eclipse on May 5, 2023, and wrote: “Last night, on 5th May 2023, we witnessed a penumbral lunar eclipse from Kolkata, India. Last night’s eclipse was pretty much observable with naked eyes during its maximum. The eclipse continued for more than 4 hours. The image is a sequence of images captured during the eclipse. All the images are captured with the same exposure settings.’ Thank you, Soumyadeep!
Full moon with faint shading on one side.
View at EarthSky Community Photos. | Niccole Neely captured this photo on the morning of November 30, 2020. She wrote: “I woke up at 2:30 this morning to catch the Beaver Moon penumbral lunar eclipse in Phoenix, Arizona.” Thank you, Niccole!
Penumbral lunar eclipse: Full moon with shading on one side.
View at EarthSky Community Photos. | Nils Ribi in Sun Valley, Idaho, caught the November 30, 2020, penumbral lunar eclipse, too. He wrote: “The penumbral eclipse of the full moon, November 30, 2020, 2:43 a.m. Mountain Standard Time, the time of greatest eclipse, in Sun Valley, Idaho. It was nice to see that the eclipse was not that faint here.” Thank you, Nils!

More resources

Total lunar eclipse: Brightly colored covers of three large-format books.
Thank you, Fred Espenak, for granting permission to reprint this article. For the best in eclipse info – from a world expert – visit Fred’s publications page.

Bottom line: A penumbral lunar eclipse – lasting over four hours – happens overnight tonight. It’s visible from eastern Europe, Africa, Asia, Australia, New Zealand, Antarctica and Indonesia.

Visit Timeanddate.com to get an exact timing of the eclipse from your location.

EarthSky’s monthly night sky guide: Visible planets and more

Posted 
May 5, 2023
 in 
Astronomy Essentials

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