A blood moon is the dramatic purple glow of the moon throughout a complete lunar eclipse.
It occurs when Earth’s shadow utterly covers a full moon, filtering daylight by our environment and turning the lunar floor deep purple or coppery brown. Because the moon’s orbit is barely tilted, most full moons do not line up completely. But after they do, the result’s a placing blood moon eclipse, a phenomenon that has fascinated skywatchers for hundreds of years.
When is the next blood moon?
The next blood moon will occur on March 3, 2026. It will be visible to skywatchers across North America and will be the last total lunar eclipse anywhere on Earth until New Year’s Eve 2028-2029.
You can catch up with the latest lunar eclipse news and events with our lunar eclipse live blog.
Why is it called a blood moon?
It’s called a blood moon because during a total lunar eclipse, Earth’s atmosphere filters sunlight and scatters blue light, leaving the moon glowing red or coppery.
How often do blood moons occur?
About 29% of all lunar eclipses are whole lunar eclipses. Earth experiences roughly two lunar eclipses per 12 months. Most locations on Earth can count on to see a complete lunar eclipse about as soon as each 2.5 years.
What occurs throughout a blood moon?
During a total lunar eclipse, the moon is fully inside Earth’s shadow, and that’s when the striking blood moon effect appears. Sunlight passing through Earth’s atmosphere gets filtered and scattered, blue light is removed, leaving only the longer red and orange wavelengths to reach the moon. This is the same effect that makes sunrises and sunsets appear red, and it bathes the moon in a coppery glow.
The exact shade of a blood moon can vary depending on atmospheric conditions. Volcanic ash, wildfire smoke, dust, or pollution can make it appear darker or more intense. According to NASA, two to 4 lunar eclipses happen every year, and every could be seen from roughly half the planet. While planets and moons throughout the photo voltaic system solid shadows, solely Earth produces lunar eclipses that utterly cowl its moon — a cosmic alignment that gained’t final endlessly, because the moon is slowly drifting away by about 1.6 inches (4 centimeters) every year.
While there are planets and moons everywhere in the photo voltaic system, solely Earth is fortunate sufficient to expertise lunar eclipses as a result of its shadow is simply giant sufficient to cowl the moon utterly. The moon is slowly drifting away from our planet (at roughly 1.6 inches or 4 centimeters a 12 months) and this case will not persist endlessly. There are roughly two to 4 lunar eclipses yearly, in keeping with NASA, and each is seen over about half the Earth.
How a blood moon saved Christopher Columbus
Some historical cultures did not perceive why the moon turned purple, causing fear. At least one explorer — Christopher Columbus — used this to his advantage in 1504.
According to a Space.com Skywatching columnist Joe Rao, Columbus and his crew were stranded on an island now known as Jamaica. At first the Arawak people who lived there were welcoming, but over time, Columbus’ crew grew restless and murdered or robbed some of the indigenous people. Understandably, the indigenous people weren’t eager to help the crew search for food, and Columbus realized famine was drawing near.
Columbus had an almanac with him foretelling when the subsequent lunar eclipse would happen. Armed with this info, he instructed the Arawak that the Christian god was sad that Columbus and his crew acquired no meals. God would flip the moon purple as a logo of his anger, Columbus mentioned. As the occasion came about, frightened folks “with great howling and lamentation came running from every direction to the ships laden with provisions, praying to the Admiral to intercede with his god on their behalf,” in keeping with an account by Columbus’ son Ferdinand.
Additional resources
If you have a budding astronomer at home who wants to learn more about eclipses check out Solar and Lunar Eclipses (Explore Outer Space) by Ruth Owen or check out NASA’s Space Place webpage on the several types of moons.
Bibliography
K. G. Strassmeier et al “High-resolution spectroscopy and spectropolarimetry of the total lunar eclipse January 2019,” Astronomy & Astrophysics, Volume 653, March 2020, https://doi.org/10.1051/0004-6361/201936091
Natural History Museum, “Lunar eclipse guide: what they are, when to see them and where,” May 27, 2021.
Royal Museums Greenwich, “How to see a lunar eclipse,” January, 2022.
Jessica Marshallsay, “Blood moon rising: How lunar eclipses might help us find life on other planets,” The University of Queensland, January, 2022.