Nebra sky disc: Prehistoric star map's Bronze Age pedigree in question -- by 1,000 years

This image shows the Nebra sky disc in 2002. The disc includes a crescent moon as well as other cosmic features and depicts an abstract representation of a starry night.

(CNN)The Nebra sky disc, one of Germany's most heralded prehistoric artifacts, is often considered the world's oldest depiction of the cosmos. For a relatively small object -- the gold-speckled disc is only 12 inches wide -- it has produced a large amount of controversy.

In fact, the Nebra sky disc's sordid history reads like a Dan Brown novel, involving looters, court hearings, conflict between archaeologists and even allegations of revenge.
The sky disc was reportedly unearthed in 1999 near the town of Nebra, Germany, by looters who sold it to black-market dealers. It was recovered by law enforcement several years later, and the looters were prosecuted in court. Today, it's exhibited in the State Museum of Prehistory in Halle.
    But there were inconsistencies in the looters' stories about how they acquired the artifact. And experts continue to debate the exact origins and history of the disc, which is widely considered to be from the Bronze Age, about 3,600 years ago.
      Now, the saga continues as a new analysis has suggested the Nebra sky disc could be about 1,000 years younger than previously thought.
        Based on analysis of the soil attached to the disc and the iconography of its decorations, two scientists concluded that the artifact is more likely to be from the Iron Age, dating between about 2,800 and 2,050 years ago. The study published this month in the German journal Archaeological Information.

        A questionable find

          The authors of the study, Rupert Gebhard, director of the Bavarian Archaeological State Collection in Munich, and Rüdiger Krause, professor of prehistory and early European history at Goethe University Frankfurt, argued the exact location of the disc's discovery might not be the Mittelberg hill near Nebra, Germany -- the spot where one looter directed authorities.
          "One principle of the looters is to never tell the truth about the site you have excavated," Gebhard said. "What's interesting is that nobody has discovered anything on the Mittelberg before this discovery, and nobody has discovered anything on the Mittelberg after. From this point of view, it's highly unusual that the site is the real site."
          The date of the disc was determined in part by the objects found alongside it -- Bronze Age swords, axes and a prehistoric chisel. But based on soil attachments found on all the objects, the authors wrote, it's also not certain they were originally found together.
          The new study casts doubt on the artifact's status as the oldest depiction of the heavens and could tarnish its reputation as what UNESCO has called "one of the most important archaeological finds of the 20th century."

          Museum refutes latest study

          The German state of Saxony-Anhalt, which hosts the disc in its state museum, is strongly refuting Gebhard and Krause's research.
          "The colleagues not only ignore the abundance of published research results in recent years, their various arguments also are easily refuted," Deputy State Archaeologist Alfred Reichenberger said in a statement, adding that some of the claims in the new research article are inconsistent and "not comprehensible."