Nebra Sky Disc: A sky map that is 3600 years old

The British Museum in London has started displaying an ancient object. It is the Nebra Sky Disc, thought to be the world’s oldest concrete depiction of stars. The Museum got it as a loan from Germany’s State Museum of Prehistory in Halle. The Nebra Sky Disc will be available for public viewing next year when the British Museum opens an exhibition on Stonehenge in February 2022. 

What is the Nebra Sky Disc? 
About 3,600 years ago, this disc was buried in a ritual along with two swords, axes, two spiral arm-rings and one bronze chisel near Nebra of Germany. The burial of these objects was done as a dedication to gods. The exact age of the disc is disputed by archaeologists, with claims ranging between 3,700 years and 2,500 years. The exact purpose of the disc is yet not determined. It might be an astronomical clock, a work of art or a religious symbol. Given its age and importance, this disc is valued about $11 million.  Scientists think it is part of a pair, and the other part is yet to be discovered. 

How the Nebra Disc map the skies? 
The Archaeology magazine, published by the Archaeological Institute of America notes that the sky in the disc is an observation from atop the Mittelberg Mountain, near the modern village of Nebra, Germany. The depiction is in 5 phases of the sky. In the first phase, the disc illustrates the night sky with 32 gold stars, including the constellation Pleiades. An orb representing the sun or a full moon and a crescent moon are then represented on the disc. This illustration served to synchronise the lunar and solar years by inserting a leap month. It is unbelievable, but prehistoric man actually noticed these differences in the sky above and tried to map it all, measuring time before the concept of ‘time’ came to be.  

How was the Nebra Disc discovered?  
The bronze disc was discovered in 1999, surprisingly by treasure hunters using a metal detector and looking around in Nebra. The excavation was illegal, and the discoverer sold the disc. It was recovered from a black-market raid in Switzerland along with some Stone Age weapons.