A “blood moon” occurs when Earths moon is in a total lunar eclipse. The difference in these two cycles has to do with the relative positions of the sun, Earth and moon, which alter during the moons orbit.Lunar eclipses can just occur throughout a complete moon, when the sun totally illuminates the surface. Earth passes in between the sun and the moon and cuts off the sunlight, causing an eclipse.If Earth partially blocks the sun, and the darkest part of its shadow falls across the moons surface, it is called a partial eclipse. If an eclipse takes location shortly after a volcanic eruption, the particles in the atmosphere will make the moon look darker than usual.While there are planets and moons all over the solar system, only Earth is fortunate enough to experience lunar eclipses because its shadow is just large enough to cover the moon completely. There are roughly two to four lunar eclipses every year, according to NASA, and each one is noticeable over about half the Earth.How a blood moon saved Christopher ColumbusSome ancient cultures didnt understand why the moon turned red, triggering fear.
A “blood moon” occurs when Earths moon remains in an overall lunar eclipse. While it has no unique huge significance, the view in the sky is striking as the usually whiteish moon becomes red or ruddy-brown. The moon orbits around Earth, while Earth orbits around the sun. The moon takes about 27 days to orbit Earth and goes through regular stages in a 29.5-day cycle. The difference in these two cycles pertains to the relative positions of the sun, Earth and moon, which change throughout the moons orbit.Lunar eclipses can just take place throughout a moon, when the sun completely brightens the surface. Typically a complete moon has no eclipse due to the fact that the moon orbits in a slightly different plane than the Earth and the sun do. However, at times the airplanes coincide. Earth passes in between the sun and the moon and cuts off the sunshine, causing an eclipse.If Earth partly blocks the sun, and the darkest part of its shadow falls throughout the moons surface, it is called a partial eclipse. You will see a black shadow taking a bite out of the moon. Often, the moon goes through the lighter part of Earths shadow, causing a penumbral eclipse. Just skilled skywatchers will be able to discriminate, since the moon only darkens really slightly.During a full eclipse, however, something magnificent takes place. The moon is completely in Earths shadow. At the very same time, a bit of light from Earths daybreaks and sundowns (on the disk of the planet) falls on the surface area of the moon. Since the light waves are stretched out, they look red. When this traffic signal strikes the moons surface area, it also appears red. Skywatcher Keith Burns took this montage of images, which shows the Dec. 20, 2010, total lunar eclipse. The montage won a NASA contest to become an official NASA/JPL wallpaper for the public. (Image credit: Keith Burns/NASA/JPL)How red the moon appears can depend upon how much contamination, cloud cover or particles there remains in the environment. If an eclipse takes location quickly after a volcanic eruption, the particles in the environment will make the moon appearance darker than usual.While there are planets and moons all over the solar system, just Earth is lucky enough to experience lunar eclipses due to the fact that its shadow is simply big enough to cover the moon entirely. The moon is slowly drifting away from our planet (at approximately 1.6 inches or 4 centimeters a year) and this scenario will not continue permanently. There are approximately 2 to 4 lunar eclipses every year, according to NASA, and each one shows up over about half the Earth.How a blood moon conserved Christopher ColumbusSome ancient cultures didnt understand why the moon reddened, triggering worry. At least one explorer– Christopher Columbus– utilized this to his benefit in 1504. According to a Space.com Skywatching columnist Joe Rao, Columbus and his team were stranded on an island now known as Jamaica. Initially the Arawak people who lived there were inviting, but gradually, Columbus crew grew uneasy and killed or robbed some of the natives. Naturally, the native people werent excited to help the team look for food, and Columbus recognized scarcity was approaching. A blood moon seen over California in 2018. (Image credit: Getty Images )Columbus had an almanac with him foretelling when the next lunar eclipse would happen. Armed with this information, he informed the Arawak that the Christian god was dissatisfied that Columbus and his crew got no food. God would turn the moon red as a symbol of his anger, Columbus said. As the occasion took location, scared people “with terrific howling and lamentation came ranging from every direction to the ships loaded with arrangements, hoping to the Admiral to intercede with his god on their behalf,” according to an account by Columbus kid Ferdinand.When is the next blood moon? The next overall lunar eclipse, and for that reason the next blood moon, will be May 16, 2022. Numerous partial and penumbral lunar eclipses occurred considering that the previous overall lunar eclipse on May. 25-26, 2021, and NASA has a list of all the lunar eclipses up until 2100. Additional resources If you have a budding astronomer in your home who wishes to discover more about eclipses check out Solar and Lunar Eclipses (Explore Outer Space) by Ruth Owen or have a look at NASAs Space Place website on the different 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/10.1051/0004-6361/201936091Natural 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 may assist us discover life on other planets,” The University of Queensland, January, 2022.