According to historical accounts extant today, the natural satellite was hidden behind an impenetrable cloud of volcanic ash in the skies of the Northern Hemisphere in 1110. Until recently, it was believed that the moon was hidden as a result of the eruption of the volcano Hecla, but now scientists have found out that it was another volcano.
There is a hypothesis that the eruption of the Hecla volcano in 1104 led to a huge amount of volcanic material in the atmosphere, which literally made the moon disappear from the night sky. New research has shown that the Hecla volcano simply could not have emitted enough ash to cover the Moon – an analysis of ice cores from 900-year-old layers, among other things, has shown this.
Paleoclimatologist Sébastien Guillier of the University of Geneva (Switzerland) and the scientists under his supervision studied all available materials and decided that the disappearance of the moon in Europe, observed from 1110 to 1120, was due to the volcanic eruption of Asama in Japan. Asama was responsible for the severe cooling that began in Europe in 1109 and lasted several years. But scientists do not rule out that there could have been other volcanic eruptions that contributed to the cooling and disappearance of the Moon.