One of Germany's most famous ancient artifacts may not be what it seems, if a new study is to be believed.

Fierce debate over the Nebra Sky Disk has been reignited by a new study that suggests it is at least 1,000 years younger than previously thought, and probably doesn't have any of the elaborate meanings proposed for it.

The 12-inch-wide (30 centimeters) bronze disk inlaid with gold circles, arcs and crescents was reportedly unearthed in 1999 near the town of Nebra, in Germany's Saxony-Anhalt state. 

It was widely hailed as one of the most stunning ancient artifacts ever found. But controversy has surrounded it since its discovery.

Experts have long debated where the disk originated and what meaning, if any, it holds; some have even declared it is fake (and created very recently) — although scientific tests suggest it's an authentic artifact that may date from Europe's pre-Celtic Bronze Age, up to 3,800 years ago.

If that dating is correct, then the Nebra Sky Disk is the oldest-known representation of the heavens anywhere in the world, said Jan-Heinrich Bunnefeld, an archaeologist at Saxony-Anhalt's State Museum for Prehistory in the city of Halle, where the disk is now on display (The next oldest is an ancient Egyptian star map on the ceiling of a tomb from about 3,500 years ago).

"The Nebra Sky Disc features the oldest concrete depiction of cosmic phenomena," Bunnefeld told Live Science in an email. "It is a key find, not only for the discipline of archaeology, but also for astronomy and the history of religions."

Ancient artifact

But a new study casts doubts on the origins and meaning of the Nebra Sky Disk. 

Writing this month in the journal Archäologische Informationen, University of Munich archaeologist Rupert Gebhard and Rüdiger Krause, an archaeologist at Goethe University in Frankfurt, argue that the artifact could not have been unearthed at the location near Nebra, according to a statement.

That also means the sky disk probably isn't from the Bronze Age at all. In addition, a new examination of its iconography suggests the artifact dates to the period of the Celtic Iron Age between about 2,800 and 2,050 years ago, the researchers wrote.

The study has created outrage in parts of the archaeological scene in Germany, where the Nebra Sky Disk is considered a national treasure and an emblem of early European civilization — and where any challenges to its provenance or authenticity are aggressively confronted.

"It's like Beethoven's Ninth," Gebhard told Live Science, referring to the composer's famous symphony, a nationally revered symbol of German achievement. 

"That makes it difficult for me … you can understand that people are not very happy about this."

Bronze Age hoard

The biggest reason the new study casts doubt on the sky disk's provenance is that scientific evidence suggests it was not part of a hoard of Bronze Age axes, swords and bracelets allegedly unearthed by treasure hunters near Nebra in 1999, although it was initially thought to be, Gebhard said.

The collectors sold the disk and hoard to a black-market collector for around 70,000 German marks ($42,000) and it was sold on for up to a million German marks ($600,000), until police recovered the hoard in 2002 and handed it over to state archaeologists.

A court found the two treasure hunters guilty in 2005 for the illegal excavation, sentencing the pair to several months in jail.

Statements made by the treasure hunters in their attempts to appear to be cooperating with authorities explains the resulting confusion about the location of the artifacts, Gebhard said.

But archaeological evidence, soil analysis and studies of trace isotopes (variations of an element with different numbers of neutrons) in the metals of the disk show it must have been found somewhere else, and then sold as part of the hoard from Nebra: "If you go back to the basics, then you won't find any argument that these objects belong together," he said.

Gebhard hopes the treasure hunters will eventually explain where they actually unearthed the Nebra Sky Disk, information that would cast new light on its origins.

"I think our article now brings some movement in this story," he said. "I hope it will be the first step to get some information about the original site."

Disputed origins