The Nebra Sky Disc is a bronze disc about 32 centimetres across, inlaid with gold shapes usually read as the sun or full moon, a crescent, and stars including a cluster resembling the Pleiades, with later-added arcs marking the horizon. It is often called the oldest known concrete depiction of the cosmos. It was looted from a Bronze Age hoard on the Mittelberg near Nebra in 1999 and recovered in a police operation in 2002, and is now displayed at the State Museum of Prehistory in Halle.
The 2020 challenge to the disc's Bronze Age date, mounted by archaeologists Rupert Gebhard and Ruediger Krause, argued specifically that because the hoard was recovered by looters rather than excavated in place, the association between the disc and the bronze weapons dated to around 1600 BC could not be treated as secure, opening the possibility the disc itself belonged centuries later, in the Iron Age. The thirteen-author rebuttal published the same year in Archaeologia Austriaca countered with metallurgical, stylistic and find-context evidence assembled since the original recovery, and the State Museum of Prehistory in Halle, which holds the object, has continued to present the Bronze Age dating as the scholarly consensus while noting the dissent exists. Beyond the dating dispute, the disc's astronomical content has drawn its own literature: the golden arcs added to the disc after its original manufacture are read by some researchers as marking the angle between summer and winter solstice sunset as observed from the Mittelberg hill itself, an interpretation that, if correct, would make the object evidence of sustained horizon observation rather than only a symbolic sky-map, though this reading remains a proposed interpretation rather than an established fact.