The Nebra sky disk is a 3,600-year-old bronze disk inlaid with gold stars, sun, & moon (& "sun ship"?). The disk + 2 bronze swords, 2 hatchets, a chisel, and fragments of spiral bracelets were discovered in 1999 by 2 Germans while they were treasure-hunting with a metal detector. 
"The style in which the disk is executed was unlike any artistic style then known from the period, with the result that the object was initially suspected of being a forgery, but is now widely accepted as authentic" -Wikipedia
"The two arcs span an angle of 82°, correctly indicating the angle between the positions of sunset at summer and winter solstice at the latitude of the Mittelberg (51°N)." ancient-origins.net/ancient-techno…
"This ancient enigmatic disk probably depicts the midnight culmination of the #Pleiades for calendar leap months and festival celebration." johnpratt.com/items/docs/201…
