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the significance of the blood moon in japanese culture

The world we live in is full of magical creations and happenings. One of them is the miracle of a moon that appears as red as blood that occurs not as often as we would prefer it to, but when it does it brings everyone around the world gazing up at the sky in awe.


The blood moon is a rare sight, making it spellbinding in itself. In our present day, we have science to explain why Earth’s natural satellite turns red once every few years. But can you imagine what the people in ancient times think about the natural light in the night sky suddenly becoming blood red one evening? It would’ve raised more than one question and have alarmed most. The Japanese have been around for so long that it’s not surprising that the people have their own superstitions and mythology on the blood moon.


We are blessed to be just a click of a button away from feeding our curiosity about the world, but the people in the olden days weren’t as lucky. This natural phenomenon of a blood moon has been associated with numerous things, each culture having a different belief from the other. Explore how the blood moon comes about as well as what the Japanese thought about this beautiful crimson light in the night sky.

What is a blood moon?


The moon is either white or yellow in colour all year round when it’s visible in the sky — that’s pretty common. So, how can it turn from that to crimson, blood red? A blood moon is only possible during a full moon, which happens when the moon is on the opposite side of the Earth from the sun. Because it is being fully illuminated by the sun, it can be seen from Earth as a full, round moon.


While a full moon happens every lunar month, a lunar eclipse only happens every so often. That’s because the moon doesn’t orbit in the same position each time. Its orbit is tilted with respect to the Earth’s orbit around the sun. A lunar eclipse happens about two to four times a year.


A lunar eclipse happens during a full moon, but it only occurs when the moon, Earth and sun are in perfect alignment, with the Earth being right in the middle of the moon and sun. When this happens, the Earth’s shadow falls onto the moon. This partial or full blockage of the sun’s light causes the moon to take on a red tint. Some might see it as orange-red, others as coppery red — it all depends on where you are in the world. Regardless of the exact tint, this type of eclipse has been named as the blood moon.

Types of lunar eclipses


There isn’t just one type of lunar eclipses. The blood moon occurs during one of the few types of lunar eclipses but not all of them, so don’t be confused with the terms. In total, there are three types of lunar eclipses — the total lunar eclipse, the partial lunar eclipse and the penumbral lunar eclipse. The various types depend on how the moon passes through the Earth’s shadows, the umbra and the penumbra. Depending on which shadow the moon passes, it’ll affect the type of lunar eclipse that happens. If the moon passes through the penumbral shadow, it’s not as visible as when the moon is in the umbral shadow.


At this present time, the moon is in the perfect distance away from the Earth for the Earth’s shadow to fully cover the moon during the full moon. Billions of years ago, the moon was so much closer to the Earth, but it has since been inching away from the planet. In a few billions of years from now, the moon will be extremely further away from the Earth, and lunar eclipses might not be possible to see then.

Total lunar eclipse


The total lunar eclipse happens when the moon is in the Earth’s full umbral shadow. Being in such a dark area doesn’t make the moon fully disappear, but the Earth will reflect a slight amount of light that gives the moon an eerie vibe. This is when the blood moon is visible on Earth. When you’re on the moon during this time, you’d see a black disk that is Earth blocking the sun entirely, but also a ring of light around the planet — this is the light that you see reflecting on the moon to the Earth.

Partial lunar eclipse


Not every lunar eclipse is a total lunar eclipse. Some of them are partial lunar eclipses, which means the sun, moon and the Earth aren’t fully aligned. This will result in the Earth’s shadow being partially blocking the moon, and from Earth you’ll see that the moon appears to have been bitten out — by the Earth’s shadow, of course. 

Penumbral lunar eclipse


This type of lunar eclipse isn’t as exciting as the other two as it’s not as visible. The penumbral lunar eclipse happens when the moon goes through the Earth’s outer shadow which is the penumbral shadow. The moon will be slightly shaded by the Earth’s shadow, but unless you’re a seasoned skywatcher, you would probably not notice it.

Why does the moon turn red?


As mentioned before, the blood moon only happens during the total lunar eclipse during a full moon. When the moon is fully shaded by the Earth, the only light source the moon is getting is from the Earth’s reflection of the planet’s atmosphere. The air molecules on Earth scatter out the blue light and the red light is the least altered in the filtration process, hence it reflects onto the moon and makes it a visible crimson red from the Earth.

How red the moon looks depends on the amount of dust, pollution and cloud there is in the atmosphere. It can appear differently from different parts of the world. If there are more particles in the atmosphere, the red colour of the moon will be darker. If it’s a clearer atmosphere in the sky, then the tint of red will be lighter. 

Myths on the blood moon


The moon has been linked to countless mythology throughout history and in various cultures, not only in Japan — more often than not they’re related to something bad. There was no way a blood moon appeared in ancient times without instilling a mixture of awe and fear, especially since they have no idea how it became that way. Some cultures and civilisations believed that the rare natural phenomenon of a blood moon would bring about fortune, but most of the civilisations related the blood moon to bad omen and doom.

Mythology all around the world


The world is huge, and back then there wasn’t the convenience of communication across the  globe as easily as we can now. Hence, the creation of various myths from different civilisations were inevitable. 


Ancient Rome used to practice screaming and shouting during a blood moon on a total lunar eclipse. They believed that the blood moon brings about demons during the unfortunate night.


The ancient Chinese as well as the Todas from the Nilgiris believed that the blood moon was caused by a wild animal biting the sun or the moon. As it is a symbol of bad omen, the people would fast during the eclipse to prevent it from recurring again as well as ringing their ancient local bells extremely loud. The Incan Empire of South Africa, the Vikings and the Vietnamese also believed that there were some sort of wild creature that devoured the moon that caused it to turn red.


The ancient Hindus believed that the Hindu demon, Rahu, stole the immortality elixir and when the sun and the moon found out, they reported it to the Hindu god, Vishnu, who then sliced Rahu’s head off. Because Rahu has consumed the elixir but didn’t go through his body, the head is immortal while the body dies away. The head of Rahu would chase the sun and the moon for reporting him, and every so often he would catch them and swallow them, but because he doesn’t have a body, it would just fall out of the bottom of his head, leaving a red tint on them. 


The world’s earliest civilisation was in MEsopotamia in Southwest Asia, and the Mesopotamian believed that when the moon turned red, it was being attacked. They linked it to their king potentially being assaulted as well. The people would hide their king during a total lunar eclipse that brought about a blood moon and installed a substitute ruler until the eclipse was gone. This belief spread through Egypt, Middle East as well as the Mediterranean.

Japanese mythology


It shouldn’t be surprising that the Japanese have a few various myths when it comes to the blood moon, as Japan wasn’t so much a single country but consisted of multiple civilisations that might as well be considered individual countries. 


In the Middle Ages of Japan, during the end of the Heian period and the beginning of the Mamkura period, the Japanese people then took the blood moon as a sign that something bad would happen. Many historical names like the Kujo Kanemi and Minamoto no Yoritomo have written about the blood moon. Kujo practiced a Buddhist method similar to a sutra to prevent bad happenings during a blood moon while the first shogun of the Kamakura Shogunate stayed indoors to avoid the blood moon lunar eclipse. A famous poet in the Heian period named Saigyo also mentioned in one of his poems regarding the lunar eclipse when the blood moon could be seen, and said that the world looked at it with a bad reputation.


Another myth of the Japanese regarding the blood moon lunar eclipse is linked to the ancient Japanese mythology that’s about the sun goddess, Amaterasu. It was written in the Kojiki, the oldest and most ancient Japanese books in history, that Amaterasu entered a cave because of a blood moon lunar eclipse and had to be lured out by a mirror.

Superstitions of the blood moon


It may be a coincidence, but the people from the ancient times didn’t think so. There have been superstitions that the blood moon affects the Earth and the people on it negatively — in the forms of natural disasters and alterations of the people’s behaviour.



Even till this day, many still believe that a blood moon can cause earthquakes around the world. Some studies did show that an earthquake that happens during a blood moon happened to be stronger than normal. However, there have been various studies that concluded no apparent connection between earthquakes and the blood moon.

Tides & tsunamis


Some believed that a full moon, and more prominently a blood moon, can affect the tides and thus cause tsunamis. While a lunar eclipse means that the moon is closer to the Earth and affects the tides because of the gravitational forces exerted, studies have shown that tsunamis are caused by geographical events on Earth rather than tidal effects and the blood moon.

Affect human behaviour


For quite a while, the blood moon is believed to affect one’s behaviour — hence words like “lunatic” and “lunacy” came about as it derived from the Latin word for moon. Some even believed that the blood moon can make one react violently and crazily. Fortunately, there are no scientific links to these superstitions.

The significance of the moon to the Japanese


Even though Japan is known as “The Land of the Rising Sun”, the country and its people have long claimed that the moon is an important part of their culture and beliefs. 


Japan’s religion is a mixture of traditional Shintoism as well as Zen Buddhism — both of which appreciates the beauty of the earthly creations. While the Shintoism belief focuses on the spirit of nature, Zen Buddhism focuses on selflessness and enlightenment. In Shintoism, the Japanese has a moon god called Tsukuyomi, which is the brother to the sun goddess Amaterasu. Even though he’s not as significant as his sister, he represents all the positive things of the night — dreams, spirituality, and balance of energy. In Zen Buddhism, however, the moon represents enlightenment. 


Regardless of the religion, the Japanese as a whole looks up to the moon as a positive influence in their beliefs. There is even a holiday in Japan for moon-viewing called “Tsukimi”, which falls in autumn to honour the autumn moon. The ancient Japanese used to look up to the moon in mid-autumn to show appreciation of the fruits of nature. It’s a whole celebration by serving freshly-harvested foods under the clear full moon. Even till this day, the Japanese celebrates the harvest moon by holding festivals specially for it.

When is the next blood moon?


The latest blood moon during a total lunar eclipse fell on January 20th, 2019. The blood moon that year was especially special as it was also a supermoon — that means the moon appears bigger to the people on Earth than any other time. 


It’s predicted that there wouldn’t be another blood moon until the year 2021 in May, and the one after that would be in 2022 during May as well.

The Wrap-Up


The moon is a magnificent thing that greets us every night. On the special occasion it appears red, people everywhere on Earth have mixed emotions on the matter — even the Japanese. With the moon deeply rooted in their culture as a positive influence, it’s a wonder how it was believed as bad omen in ancient Japanese culture. But that’s the beauty of it all — something negative can be turned positive in a split second — and in the present day, the blood moon is just seen as a beautiful natural phenomenon that’s an extremely rare sight.

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