Astronomy:Nebra sky disk

Short description: Artifact found in Nebra, Germany

The Nebra sky disk

The Nebra sky disk is a bronze disk of around 30 centimetres (11 ³⁄₄ in) diameter and a weight of 2.2 kilograms (4.9 lb), having a blue-green patina and inlaid with gold symbols. These symbols are interpreted generally as the Sun or full moon, a lunar crescent, and stars (including a cluster of seven stars interpreted as the Pleiades). Two golden arcs along the sides, interpreted to mark the angle between the solstices, were added later. A final addition was another arc at the bottom surrounded with multiple strokes (of uncertain meaning, variously interpreted as a solar barge with numerous oars, the Milky Way, or a rainbow).

The disk has been attributed to a site in present-day Germany near Nebra, Saxony-Anhalt, and was originally dated by archaeologists to c. 1600 BCE. Researchers initially suggested the disk is an artifact of the Bronze Age Unetice culture, although a later dating to the Iron Age has been proposed as well.

If its Bronze Age dating is accurate, the Nebra sky disk features the oldest concrete depiction of the cosmos yet known from anywhere in the world. In June 2013 it was included in the UNESCO Memory of the World Register and termed "one of the most important archaeological finds of the twentieth century."

Discovery

The disk, two bronze swords, two hatchets, a chisel, and fragments of spiral bracelets were discovered in 1999 by Henry Westphal and Mario Renner while they were treasure-hunting with a metal detector. Archaeological artifacts are the property of the state in Saxony-Anhalt. The hunters were operating without a license, and knew their activity constituted looting and was illegal. They damaged the disk with their spade and destroyed parts of the site. The next day, Westphal and Renner sold the entire hoard for 31,000 DM to a dealer in Cologne. The hoard changed hands within Germany during the next two years, being sold for up to a million DM. By 2001 knowledge of its existence had become public. In February 2002 the state archaeologist, Harald Meller, acquired the disk in a police-led sting operation in Basel from a couple who had put it on the black market for 700,000 DM. The original finders were eventually traced. In a plea bargain, they led police and archaeologists to the discovery site. Archaeologists opened a dig at the site and uncovered evidence that supports the looters' claims. There are traces of bronze artifacts in the ground, and the soil at the site matches soil samples found clinging to the artifacts. Now the disk and its accompanying finds are held at the State Museum of Prehistory in Halle, Saxony-Anhalt, Germany.

The two looters received sentences of four months and ten months, respectively, from a Naumburg court in September 2003. They appealed, but the appeals court raised their sentences to six and twelve months, respectively.

The discovery site is a prehistoric enclosure encircling the top of a 252 metres (827 ft) elevation in the Ziegelroda Forest, known as Mittelberg ("central hill"), some 60 km west of Leipzig. The surrounding area is known to have been settled in the Neolithic era, and Ziegelroda Forest contains approximately 1,000 barrows.

The enclosure is oriented in such a way that the sun seems to set every solstice behind the Brocken, the highest peak of the Harz mountains, some 80 km to the north-west. The treasure-hunters claimed the artifacts were discovered within a pit inside the bank-and-ditch enclosure.

Dating

The swords found with the disk

Other associated finds: chisel, axeheads, bracelets

The precise dating of the Nebra sky disk depended upon the dating of a number of Bronze Age weapons, which were offered for sale with the disk and said to be from the same site. These axes and swords can be dated typologically to the mid-second millennium BCE. Radiocarbon dating of a birchbark particle found on one of the swords to between 1600 and 1560 BCE confirmed this estimate. This corresponds to the date of burial, at which time the disk had likely been in existence for several generations.

Research published in 2020 by archaeologists from Goethe University Frankfurt and Ludwig Maximilian University of Munich casts doubt on this dating, however. After reevaluating prior research and the circumstances of the disk's discovery, the authors argue that the disk was likely not part of the cache of Bronze Age weapons, and therefore, cannot be dated with these artifacts. Instead they assert that the disk should be evaluated as an individual find. Since the authors contend it bears hallmarks of an Iron Age item, they place its origins instead in the first millennium BCE. This younger age, they argue, would significantly change the sometimes far-reaching cultural and historical conclusions that have been attributed to the disk.

Origin of the metals

According to an initial analysis of trace elements by x-ray fluorescence by E. Pernicka, then at the University of Freiberg, the copper originated at Bischofshofen in Austria, while the gold was thought to be from the Carpathian Mountains. A more recent analysis found that the gold used in the first phase was from the River Carnon in Cornwall, United Kingdom. The tin present in the bronze was also of Cornish origin.

History

As preserved, the disk was developed in four stages (Meller 2004):

1. Initially the disk had thirty-two small round gold circles, a large circular plate, and a large crescent-shaped plate attached. The circular plate is interpreted as either the Sun or the full Moon, the crescent shape as the crescent Moon (or either the Sun or the Moon undergoing eclipse), and the dots as stars, with the cluster of seven dots likely representing the Pleiades.
2. At some later date, two arcs (constructed from gold of a different origin, as shown by its chemical impurities) were added at opposite edges of the disk. To make space for these arcs, one small circle was moved from the left side toward the center of the disk and two of the circles on the right were covered over, so that thirty remain visible. 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). Given that the arcs relate to solar phenomena, it is likely the circular plate represents the Sun not the Moon.
3. The final addition was another arc at the bottom, identified as a "sun boat" or rainbow, again made of gold, but originating from a different origin.
4. By the time the disk was buried it also had thirty-nine holes punched out around its perimeter, each approximately 3 mm in diameter.

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  1) On the left the full moon, on the right the waxing moon, and between and above, the Pleiades

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  2) Arcs were added on the horizon for the zones of the rising and setting sun; individual stars were shifted and/or covered

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  3) Addition of the "sun boat" or rainbow.

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  4) Diagram of the disk in its current condition (a star and a part of the sun—or full moon—have been restored)

Significance

File:Die Himmelsscheibe von Nebra (CC BY 4.0) .webm The disk may be an astronomical instrument as well as an item of religious significance. The blue-green patina of the bronze may have been an intentional part of the original artifact.

The find is regarded as reconfirming that the astronomical knowledge and abilities of the people of the European Bronze Age included close observation of the yearly course of the Sun, and the angle between its rising and setting points at the summer and winter solstices. While much older earthworks and megalithic astronomical complexes, such as the Goseck circle and Stonehenge, had already been used to mark the solstices, the disk is the oldest known "portable instrument" to allow such measurements. Pásztor, however, sees no evidence that the disk was a practical device for solar measurements.

Euan MacKie suggests that the Nebra disk may be linked to the solar calendar reconstructed by Alexander Thom from his analysis of standing stone alignments in Britain.

Authenticity

There were initial suspicions that the disk might be an archaeological forgery. Peter Schauer of the University of Regensburg, Germany, argued in 2005 that the Nebra disk was a fake and that he could prove that the patina of the disk could have been created with urine, hydrochloric acid, and a blow torch within a short amount of time. He had to admit in court that he had never held the disk in his own hands, unlike the eighteen scientists who had examined the disk.

Richard Harrison, professor of European prehistory at the University of Bristol and an expert on the Beaker people, allowed his initial reaction to be quoted in a BBC documentary:

When I first heard about the Nebra Disc I thought it was a joke, indeed I thought it was a forgery. Because it’s such an extraordinary piece that it wouldn’t surprise any of us that a clever forger had cooked this up in a backroom and sold it for a lot of money.

Although Harrison had not seen the skydisk when he was interviewed, and his skepticism was reasonable at that point, now the disk is widely accepted as authentic and is dated to roughly 1600 BCE on grounds of typological classification of the associated finds.

As the item was not excavated using archaeological methods, even its claimed provenance could have been fictitious - hence its authentication has depended on micro-photography of corrosion crystals, which has produced images of structures that could not be reproduced by a faker.

The Sky Disc Visitor Center near Nebra

Replica of the find situation of the Nebra Sky Disc for the German exhibition "The smithied sky".

Harald Meller, lecturing to the Society of Antiquaries of Scotland in April 2008, gave a list of facts supporting the authenticity of the disc, and for its having been found at the site on the Mittelberg. The most persuasive of the latter was the discovery by the archaeologists — in the pit in which the looters said they had found the metalwork — of a fragment of gold leaf exactly fitting the gap present in the gold leaf covering of the 'sun' symbol when it originally was recovered.

Exhibition

The disk was the center of an exhibition entitled Der geschmiedete Himmel (German "The smithied sky"), showing 1,600 Bronze Age artifacts, including the Trundholm sun chariot, shown at Halle from 15 October 2004 to 22 May 2005, from 1 July to 22 October 2005 in Copenhagen, from 9 November 2005 to 5 February 2006 in Vienna, from 10 March to 16 July 2006 in Mannheim, and from 29 September 2006 to 25 February 2007 in Basel.

On 20 June 2007, a multimedia visitor center was opened near the discovery site at Nebra.

The disk is part of the permanent exhibition in the Halle State Museum of Prehistory (Landesmuseum für Vorgeschichte) in Halle.

Legal issues

The State of Saxony-Anhalt has registered the disk as a trademark, which has resulted in two lawsuits. In 2003, Saxony-Anhalt successfully sued the city of Querfurt for depicting the disk design on souvenirs. Saxony-Anhalt also successfully sued the publishing houses Piper and Heyne over an abstracted depiction of the disk on book covers. The Magdeburg court assessed the case's relevance according to German copyright law. The defenders argued that as a cultic object, the disk had already been "published" approximately 3500 years earlier in the Bronze Age, and that consequently, all protection of intellectual property associated with it has long expired. The plaintiff, on the other hand, argued that the editio princeps of the disk is recent, and according to German law protected for 25 years, until 2027. Another argument concerned the question of whether a notable work of art may be registered as a trademark in the first place. The Magdeburg court decided in favour of the State of Saxony-Anhalt.

The case was appealed and on the basis of decisions from the Oberlandesgericht Düsseldorf in 2005 and the Federal Court of Justice in 2009, the initial ruling was overturned and the German Patent and Trademark Office withdrew the trademark rights. Thereafter, the State of Saxony-Anhalt registered the design of the disk as a trademark with the European Union Intellectual Property Office.

See also

• Golden hat
• Rillaton Barrow
• Mold cape
• Trundholm sun chariot
• Tumulus culture
• Antikythera mechanism

Further reading

• Ute Kaufholz: Sonne, Mond und Sterne. Das Geheimnis der Himmelsscheibe. Anderbeck, Anderbeck 2004, ISBN:3-937751-05-X
• Landesamt für Archäologie Sachsen-Anhalt (Hrsg.): Archäologie in Sachsen-Anhalt. Dt. Verl. d. Wissenschaften, Halle 1.2002, S.7–31. ISSN 0072-940X
• Frank Hagen von Liegnitz: Die Sonnenfrau Weihnachtsgabe der WeserStrom Genossenschaft, Bremen 2002.
• Harald Meller (Hrsg.): Der geschmiedete Himmel. Die weite Welt im Herzen Europas vor 3600 Jahren. Ausstellungskatalog. Theiss-Verlag, Stuttgart 2004, ISBN:3-8062-1907-9
• Katja Näther, Sven Näther: Akte Nebra – Keine Sonne auf der Himmelsscheibe? Naether, Wilhelmshorst 2004, ISBN:3-934858-02-3
• National Geographic Deutschland. Gruner + Jahr, Hamburg 2004,1, S.38–61, ISBN:3-936559-85-6
• Uwe Reichert: Der geschmiedete Himmel. in: Spektrum der Wissenschaft. Heidelberg 2004,11, S.52–59. ISSN 0170-2971
• Ch. Sommerfeld : ...Sterne mal Sterne durch Sonne ist Mond - Bemerkungen über die Nebra-Scheibe, Praehistorische Zeitschrift, 87(1) 2012, S. 110–131. ISSN 1613-0804
• Der Sternenkult der Ur-Germanen. Titelbericht im Nachrichtenmagazin DER SPIEGEL vom 25.11.2002.

External links

• Official Landesmuseum website
• Study: Bronze disk is astronomical clock, United Press International, 2 March 2006.
• Calendar question over star disc, BBC News, 25 June 2007.
• (in German) Wolfhard Schlosser, Die Himmelsscheibe von Nebra - ein früher Blick des Menschen ins Universum (astronomie.de)
• (in German) Norbert Gasch, Eine vollständig astronomische Interpretation, 17 May 2005 (astronomie.de)