blood moon

noun

variants or Blood Moon
plural blood moons or Blood Moons
: a full moon that coincides with a full lunar eclipse and that has an unusually reddish appearance

Note: The red color of a blood moon is caused by the diffusion of the sun's light into the shadow cast by the Earth.

And when it [the full moon] is eclipsed by the shadow of the Earth, it is called a blood moon as it turns a crimson color.IFLSCIENCE.com (London)
Through the little windows over the deep double kitchen sink, I saw a big sliver of blood moon sinking below the distant mountains.David Erik Nelson
also : a full lunar eclipse during which a blood moon occurs
A blood moon is the unscientific name for a total lunar eclipse, which is when Earth passes in between the sun and the moon, casting a shadow over the moon as sunlight is blocked. BreakingNews.ie

Examples of blood moon in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The result: The darkened moon glowed a distinct orange-red—a phenomenon popularly called a blood moon. Jeffrey Kluger, TIME, 14 Mar. 2025 Here's what's in store for your zodiac sign with the arrival of March's full moon on March 13, which will double as a total lunar eclipse and a blood moon Comments 'Tis the eclipse season! Skyler Caruso, People.com, 8 Mar. 2025 The full moon in March will also be a blood moon, appearing as a total lunar eclipse becomes visible across Northern America. Hannah Poukish, Sacramento Bee, 7 Mar. 2025 During this lunar phase, the moon may appear reddish in tone due to the sunlight in the earth’s atmosphere—a phenomenon also known as a blood moon. Danijela Pilic, Glamour, 13 Mar. 2025 Tonight there is a lunar eclipse during a full moon, something called a blood moon. Bethy Squires, Vulture, 14 Mar. 2025 Key moments, schedule, when to see 'blood moon' Want to snap the perfect photo of tonight's lunar eclipse? Mary Walrath-Holdridge, USA TODAY, 14 Mar. 2025 In the meantime, here are some must-see photos of the blood moon lunar eclipse from around the world. Valerie Mesa, People.com, 14 Mar. 2025 Amateur astronomers can get the best views of the blood moon by watching the eclipse in a dark environment far away from city lights, according to NASA. Hannah Poukish, Sacramento Bee, 13 Mar. 2025

Word History

First Known Use

1817, in the meaning defined above

Time Traveler
The first known use of blood moon was in 1817

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Cite this Entry

“Blood moon.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/blood%20moon. Accessed 28 May. 2025.

Last Updated: - Updated example sentences
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