Don't miss the Harvest Moon Supermoon lunar eclipse tonight! Here's what to expect

Editor's note: The Harvest Moon Supermoon delighted skywatchers worldwide on Sept. 17. You can read our wrap story here and marvel at some of the incredible photos that captured the lunar scene last night.

On the evening of Sept. 17, a partial lunar eclipse will turn the moon a murky red-brown color when Earth's shadow descends upon the lunar surface.

The partial lunar eclipse will be visible from most of North America, all of South America, Europe, all but the easternmost parts of Africa, western portions of Asia and Russia, and parts of Antarctica. 

The exact timing of the partial lunar eclipse depends on your location and you can use websites like Timeanddate.com to find specific timings based on your location. For those in the U.S. Eastern Time Zone, the eclipse will reach its darkest phase, with the moon most obscured by Earth's umbra, at approximately 10:44 p.m. EDT on Sept. 17. In Europe and Africa, the eclipse will occur during the early morning hours of Sept. 18. In London, the peak of the eclipse will be visible around 3:44 a.m. BST on September 18.

If you are unable to watch the lunar eclipse in person you can watch all the action unfold online here on Space.com. We have rounded up several lunar eclipse livestreams that are showing the Super Harvest Moon on Sept. 17. 

What causes a lunar eclipse?

During a lunar eclipse the sun, Earth and moon align so that Earth blocks sunlight from reaching the moon and casts a shadow across the lunar surface. Whether the moon sits in the penumbra or umbra will dictate the type of lunar eclipse. During a total lunar eclipse, the umbra completely covers the lunar surface. In this diagram, the moon is located in the penumbral shadow so it is experiencing a penumbral eclipse. (Image credit: Future)
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In a partial lunar eclipse, only a portion of the moon passes into Earth's shadow, creating the appearance of a hazy "bite" taken out of the lunar surface. The shadow will darken the side of the moon facing Earth. The size of this "bite" is determined by the alignment of the sun, Earth, and moon.

About 3.5% of the moon's visible surface will be covered by the darkest part of Earth's shadow, the umbra. The rest of the Full Moon will take on a slightly reddish-brown appearance as the lighter portion of Earth's shadow which doesn't entirely block the sun's light will descend upon a majority of the lunar surface.

Super special eclipse

An illustration of the moon during a partial lunar eclipse on Sept. 17, 2024. (Image credit: Starry Night Software)

The partial lunar eclipse is extra special as it also falls during a "supermoon", the second of four supermoons in a row for 2024. 

A supermoon happens when a full moon coincides with the moon's closest point to Earth in its orbit (which is elliptical-shaped). As a result, the moon appears slightly brighter and larger than usual, although the difference is subtle and hard to detect with the naked eye.

The term supermoon generally refers to a full moon within 90% of its closest approach to Earth. According to Fred Espanak, eclipse expert and retired NASA astrophysicist, there will be four supermoons in 2024, in August, September, October and November. 

A lunar eclipse never comes alone

Approximately two weeks after the lunar eclipse Earth will experience an annular solar eclipse on Oct. 2. The dazzling "ring of fire" solar eclipse will be visible over parts of the Pacific Ocean, southern Chile and southern Argentina. 

You can keep up with all the solar eclipse action with our solar eclipse live blog. We will also be streaming the eclipse live on Space.com, more details on how to watch online will be released closer to the time.

Editor's note: If you snap a great picture of the moon during September's partial lunar eclipse, and would like to share it with Space.com's readers, send your photo(s), comments, and your name and location to spacephotos@space.com. 

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Daisy Dobrijevic
Reference Editor

Daisy Dobrijevic joined Space.com in February 2022 having previously worked for our sister publication All About Space magazine as a staff writer. Before joining us, Daisy completed an editorial internship with the BBC Sky at Night Magazine and worked at the National Space Centre in Leicester, U.K., where she enjoyed communicating space science to the public. In 2021, Daisy completed a PhD in plant physiology and also holds a Master's in Environmental Science, she is currently based in Nottingham, U.K. Daisy is passionate about all things space, with a penchant for solar activity and space weather. She has a strong interest in astrotourism and loves nothing more than a good northern lights chase!