Deep Penumbral Lunar Eclipse on May 5, 2023: Visibility and Timeline

Star Walk
6 min readMay 4, 2023

On the night of May 5–6, 2023, people in much of Europe, Africa, Asia, and Australia will have a chance to see a deep penumbral lunar eclipse — deep enough to be visible to the naked eye! Check the eclipse timing for your location using the Sky Tonight or Eclipse Guide apps and keep reading this article to learn how to see this eclipse.

May 2023 lunar eclipse time & facts

  • Penumbral eclipse begins on May 5 at 15:14 GMT (11:14 a.m. EDT);
  • Eclipse reaches a maximum on May 5 at 17:22 GMT (1:22 p.m. EDT);
  • Penumbral eclipse ends on May 5 at 19:31 GMT (3:31 p.m. EDT);
  • Eclipse lasts for 4 hours, 18 minutes;
  • Umbral magnitude is -0.046;
  • Penumbral magnitude is 0.964*;
  • Eclipse takes place in the constellation Libra;
  • Note: This will be the deepest penumbral lunar eclipse until September 2042. However, penumbral eclipses are the most subtle lunar eclipses and are challenging to observe. You’ll need perfect weather and patience.

*Find out what umbral and penumbral magnitude mean further on in this article.

Timeline of the penumbral lunar eclipse on May 5, 2023. Don’t forget to convert this time to your local time zone.

What does the penumbral lunar eclipse mean?

During a penumbral lunar eclipse, only the Earth’s outer shadow, penumbra, falls on the lunar disk.

For a lunar eclipse to occur, the Sun, Earth, and Moon have to line up. However, since the plane of the Moon’s orbit is inclined to the plane of Earth’s orbit, sometimes they align imperfectly. Therefore the Earth blocks the sunlight from reaching the Moon with only the outer and lightest part of its shadow, penumbra (derived from the Latin pene — “almost” and umbra — “shadow”).

Different types of lunar eclipses.

If you already know what a penumbral eclipse is and what other eclipses there are, you might be an eclipse expert! Test your expertise with our quiz: you’ll be asked 8 true/false questions — try to get them all right.

If you want to know more about lunar eclipses in general, learn how often they happen and what causes them, read our dedicated article.

What will this lunar eclipse look like?

During a penumbral lunar eclipse, the Moon appears slightly dimmer — the difference is barely noticeable to the naked eye, especially if the sky is cloudy or the atmosphere is polluted. Near the midpoint of the eclipse, the Moon’s surface may attain a darker, brownish color, rather than its usual pearly white.

©Vito Technology, Inc.

During such eclipses, only the part of the lunar disc within the penumbral shadow darkens. On May 5, 2023, most of the lunar disc will be covered — the next such deep penumbral lunar eclipse will be in September 2042.

By the way, astronomers use the term “eclipse magnitude” while measuring an eclipse depth. Let’s delve into theory for a moment to figure out how it works.

Lunar eclipse magnitude

The lunar eclipse magnitude is the fraction of the Moon’s diameter that is covered by the Earth’s shadow. Since the Earth has two types of shadow, lunar eclipses have two types of magnitude — umbral and penumbral. Both of them are calculated at the instance of the greatest eclipse. Here are the approximate ranges of the magnitude values.

Umbral magnitude:

  • Greater than 1.0 — total eclipse;
  • 0.0 to 0.9 — partial eclipse;
  • Less than 0.0 — penumbral eclipse.

The negative umbral magnitude is the distance from the edge of the visible lunar disk to the edge of the umbral shadow divided by the Moon’s diameter.

Penumbral magnitude:

  • Greater than 2.0 — total eclipse;
  • 1.0 to 2.0 — partial eclipse;
  • Less than 1.0 — penumbral eclipse.*

*Penumbral eclipses with a penumbral magnitude of less than 0.60 usually go undetected by the naked eye.

The penumbral lunar eclipse on May 5, 2023, will have an umbral magnitude of -0.046 and the penumbral magnitude of 0.9655. In other words, during this penumbral eclipse, the Moon will fall quite deep into the penumbra, just missing the umbra. And this is just the type of penumbral eclipse that is visible to the naked eye. You just need to follow a couple of rules.

How to see a penumbral lunar eclipse?

If you’re a casual observer, just look at the Moon near the eclipse’s maximum. For Greenwich Mean Time, it will occur on May 5, at 17:22 (1:22 p.m. EDT). Convert this time for your time zone using any convenient time converter and start observing the Moon sometime before the exact moment. By the way, if you live somewhere around tall buildings, it’s better to learn the Moon’s position to make sure it won’t hide behind one of those skyscrapers. To do this, use the AR mode in Sky Tonight.

If you’re up for the challenge, you can photograph the eclipse at different stages and compare the results — the camera may be able to capture the difference that isn’t visible to the naked eye. You’ll need a tripod-mounted DSLR with a lens of at least 200mm focal length. Or set up a telescope and hold your smartphone’s camera lens over its eyepiece. Incidentally, some of the latest flagship smartphones have decent night-sky photography modes, so you could try using them instead of a DSLR. But a tripod is still a must!

Where to see the May 2023 lunar eclipse?

This penumbral lunar eclipse will be completely visible over Asia and Australia. At moonrise or moonset, it will be visible over Africa and Eastern and Central Europe.

To find out if the eclipse will be visible from your location, use the free app Sky Tonight: open the Calendar window by tapping the calendar icon at the bottom of the screen, select the month (May), and tap the date (5th). Below the calendar, you’ll see the Penumbral Lunar Eclipse event. Tap it, and you’ll see the visibility from your location under “Global Visibility”.

Map showing the areas of visibility for the penumbral lunar eclipse on May 5, 2023. For more detailed info, get the Eclipse Guide app.

When is the next lunar eclipse in 2023?

The next lunar eclipse this year will occur on October 28. It will be a partial lunar eclipse visible across Europe, Asia, Australia, Africa, North America, north and east of South America. Never miss the next eclipse with our regularly updated infographic!

Bottom line

On May 5, 2023, the deep penumbral lunar eclipse will take place; it will reach maximum at 17:22 GMT (1:22 p.m. EDT). People in Asia and Australia will be able to see it from beginning to end, in Africa and eastern and central Europe, it will be partially visible. Check the eclipse’s visibility for your location using the Sky Tonight app. During penumbral eclipses, the Moon doesn’t change its appearance dramatically — at most, you’ll see a slightly darkened lunar disk. But even a regular Full Moon in May is a remarkable event, so get out there and do some stargazing!

--

--

Star Walk

Point your device at the sky and see what stars, constellations, and satellites you are looking at 🌌✨ https://starwalk.space