“On the fifth night of the month of May, the moon appeared shining at night and, little by little, its light diminished”, recorded the unidentified scribe. There was no lunar eclipse and there were no clouds at night – the chronicle reports the brightness of the stars in a clear sky. “As soon as night came, the vision of the moon was completely extinguished, that neither the light, nor the sphere, nor anything was seen. And so it continued almost until the day and then it appeared shining “, reports the medieval chronicle. In search of explanation To explain what could have caused this frightening phenomenon, a team of scientists at the University of Geneva, Switzerland, examined tree rings, researched ice cores and sifted through historical archives. The result of the research was published in a recent article in Scientific Reports. The team found an increase in sulfate aerosols, which make up volcanic ash in ice cores in Greenland and Antarctica between the years 1108 and 1110, suggesting that the stratosphere was dusted with smoke from a recent eruption. The team also found more evidence of volcanic activity in tree rings dating from the same period. The rings revealed that 1109 was a wet and cold year in Western Europe, a climatic anomaly comparable to the effects of several other major volcanic eruptions in history, the researchers said. Disappearance of the moon After analyzing these data, the researchers concluded that a series of volcanic eruptions in Europe or Asia between the years 1108 and 1110 may have been responsible for the mysterious disappearance of the moon and for a summer devastated by rain. These volcanic events, which were little recorded by historians of the time, may have cast immense clouds of ash that traveled the world for years on end. Scientists say the volcanic smoke may have been able to extinguish the moon, without darkening the brightness of the stars. The eruptions, the scientists wrote, may also have disrupted the global climate, causing cold weather during the summer and excessive rains that triggered a food crisis in Western Europe between 1109 and 1111. Volcano eruption in Japan One of the eruptions that may have caused a cloud of smoke that caused the moon to disappear happened in Japan in 1108, said the team of scientists based on a diary written by a Japanese statesman between 1062 and 1141. The eruption of Mount Asama, in central Japan, began in late August 1108 and lasted until October of that year, recorded the Japanese leader. This eruption could have plausibly contributed to polluting the sky with enough aerosols to induce the eclipse two years later, say the scientists. Another unknown eruption, located somewhere in the southern hemisphere and also dating from 1108, probably contributed to the sulfates in the Antarctic ice core, the researchers added. Research is a reminder that our planet and its civilizations are deeply interconnected. A natural disaster in a corner of the world can reach communities thousands of miles away and even darken the moon on a clear night.
