how nebra sky disc made study 2578814

Researchers from Otto-von-Guericke University in Magdeburg, Germany, and the Saxony-Anhalt-State Museum of Prehistory, in collaboration with engineering firm DeltaSigma Analytics and coppersmith Herbert Bauer, have successfully replicated the manufacturing process of the Nebra Sky Disk, a 3,600-year-old bronze artifact depicting the cosmos. By analyzing a small sample of the disk using advanced techniques like energy dispersive X-ray spectroscopy and electron backscatter diffraction, the team determined the disk was cast and then forged at least 10 times through repeated heating and hammering. Bauer replicated this by annealing a similar metal mixture 55 times, revealing that the disk's microstructure matches a stage after 10 forging cycles, not the final 55, indicating the original preform was thinner and wider than assumed.