The moon once 'disappeared' due to... volcanic eruptions

On some days in May, around the year 1110, the Moon disappeared completely from Earth's sky. The unusual phenomenon from a millennium ago continues to baffle astronomers today.

The relationship between the Earth, the Moon, and the sun has been documented since early times. The bright golden light of the sun greets mankind and is considered the dawn of a new day, while the gentle white light of the Moon lulls us to sleep every night.

But what if one day one of those two things suddenly disappeared? What if that day lasted several weeks, or even months?

Earth's Moon

Such an event happened nearly a millennium ago, when the Earth's Moon disappeared from view for several days in May, around 1110 - a date that has not been determined due to a recording defect. copy at that time. The mystery remained unsolved until recently. Some believe that the disappearance of the Moon is simply the result of a lunar eclipse. However, the truth is not that simple.

The British astronomer George Frederick Chambers wrote about this event in his 1899 book. About 800 years after it happened, Mr. Chambers dated the Moon's disappearance to May 5, during the reign of King Henry I (unspecified year).

'The whole thing happened before midnight,' Mr Chambers wrote, 'this is clearly an example of a 'black' lunar eclipse - when the Moon becomes quite invisible instead of the familiar copper glow' .

But is that really what happened?

Figuring out the cause of the Moon's absence has become a 2020 study in the journal Scientific Reports, leading to a more complicated answer than we thought.

Scientists once surmised that an eruption of Iceland's Hekla volcano was the culprit. Mount Hekla, located at the southernmost tip of Iceland, was known by Europeans as the 'Gateway to Hell' during the Middle Ages due to its frequent eruptions.

When a large eruption occurred at Hekla around October 15, 1104, sulfur particles were released into the atmosphere. For many years, this incident was thought to be the cause behind the above mentioned Moon's disappearance.

However, new research by a team from the University of Geneva (Switzerland) has begun to reveal some new information. To see if the Hekla eruption was the sole cause of the Moon's disappearance, the researchers analyzed ice cores from Iceland and Antarctica, and eventually determined the date of the Hekla eruption. does not coincide with the date 1104 but later, in 1110.

To find the true origin, they looked through medieval records for any references to 'dark lunar eclipses' or 'black eclipses'. After much searching, the team made a breakthrough with a passage from the Peterborough Chronicle in 1110: 'The moon has been completely extinguished to the point that no light, sphere or anything can be seen. what else'.

Knowing that the absence of the Moon began around 1110, the team suggested that a cluster of volcanoes that erupted between 1108 and 1110 was most likely the real cause, not the Hekla eruption of 1104. as previously conjectured.

One of the key discoveries involved a forgotten eruption that took place in 1108 on the island of Honshu, Japan. A record by a Japanese politician, discovered by researchers and cited in the Scientific Reports study, states that a very large eruption of Mount Asama in Honshu began in late August 1108. and continued until October of that year.

'On August 29, the volcano erupted, and the fields and rice fields everywhere became uncultivable,' he wrote. 'We've never seen that in the country. It's a very strange and rare thing'.

The 1108 eruption at Asama, which the team called 'one of many major volcanic events', explains 'sufficient amounts of aerosols in the stratosphere to cause a dark lunar eclipse'. It should be noted that this is a global climate phenomenon, which science has not been able to record and explain in the past.

Volcanic eruptions from 1108-1110 led to a number of social impacts in Europe, particularly in agriculture. Researchers have also described numerous phenomena of extreme cold weather conditions, crop failure and famine. Thus, the disappearance of the Moon was the result of volcanic eruptions, but most contemporaries did not know it. They could only interpret it as a 'bad omen' when crop failures and climate change came along with the Moon's dimming.