One of the most spectacular archaeological finds in recent years is the discovery of the Nebra sky disk. The disk was buried about 3,600 years ago after a catastrophic volcanic eruption spewed huge clouds of ash into the sky, according to scientists at Mainz and Halle-Wittenberg universities in Germany.
     The 3,600-year-old Nebra sky disk, discovered in 1999 near the town of Nebra in the eastern German state of Saxony-Anhalt, is the oldest known representation of the night sky. It is thought by some to have been used as an astronomical clock to determine when to add a thirteenth month to synchronize the lunar calendar with the solar year.
     Scientists said the disk became worthless after the eruption on the Mediterranean island of Thera, located north of Crete and also known as Santorini, which ejected ash that obscured the sky all the way to Central Europe for up to 25 years. "There were cool, wet summers with devastating crop failures and exceptionally cold winters," said Francois Bertemes, a professor at Halle-Wittenberg University's Institute of European Art History and Archaeology. The changes were inexplicable to people of the Bronze Age, who were followers of a sun cult at that time. Their faith in their gods was shaken, Bertemes remarked, and "they called the priests and (the priests') rituals into question."
     Scientists said the 32cm-diameter bronze disk, dectrated with gold-leaf appliques representing the sun, moon and stars, was desecrated and buried on sacred Mittelberg Hill as an offering to the gods, accompanied by two swords decorated with gold, Bronze Age spiral bracelets and bronze axes. "The natural occurrences were almost certainly very bewildering to prehistoric people in Central Europe," said Frank Sirocko, a sedimentologist at Mainz University's Geosciences Institute.
     Sirocko and a team of researchers have analyzed the effects of weather and climate on human development for years and he has also looked into the Thera eruption. "It was surely a watershed in the Bronze Age and it's no coincidence that use of the stone circles at Stonehenge ceased 3,600 years ago, and that the Nebra sky disk was buried," Sirocko said. "Maybe the act was meant to make the gods merciful and get them to restore the previous conditions," said Bertemes, referring to the burial of the disk.
     The Nebra sky disk itself has been on permanent display at the State Museum of Prehistory in Halle (Germany) since 2008. Nebra Ark, a multimedia visitors' centre with information on the disk and its history, is located near the site where the disk was first discovered.

Source: M&C (23 August 2010)