The Nebra Sky Disk: the astronomical almanac of the bronze age
The Nebra sky disk is the oldest known representation of the celestial vault. This bronze slab (called the Nebra Disc after the name of the German town near which it was found) was probably made around 1600 BC. The depictions on the disk are not made at random or even freehand, but based on rigorous mathematical calculations which give a glimpse of astronomical expertise of the highest level.
The Nebra sky disk is one of the most interesting archaeological finds of recent years. Its importance has been underlined by its inclusion in the UNESCO's Memory of the World list, underlining that it is the oldest known astronomical representation.
Dating back to 1600 BC, the Nebra artifact is a bronze disk approximately 32cm in diameter, with a gold diagram of the heavens imprinted on it.
The disc was made towards the end of the Bronze Age by a people who lived in Europe before the arrival of the Celts. It is the oldest astronomical almanac in human history.
The artefact was found near the town of Nebra in Saxony (eastern Germany) in 1999 by two treasure hunters, Henry Westphal and Mario Renner, in a stone cavity inside an ancient bastion on the top of the Mittelberg.
The two amateur archaeologists found two bronze swords, two axes, a chisel and fragments of a spiral-shaped bracelet whose dating could be traced back to around the 1st millennium BC. Together with these artefacts they also found a bronze disk on which were inserted some gold foil.
The disc was mistakenly classified as a bucket lid and was sold illegally for 32,000 German marks. After passing through several hands, in 2002 it was offered on the black market for 700 thousand marks.
On behalf of the Ministry of Culture and the Ministry of the Interior, and of the Archeology Agency of the Sachsen-Anhalt region which claimed ownership, the archaeologist Harald Meller, posing as a normal buyer, made an appointment with the fences, where he showed up with the Swiss police.
The disk, together with other archaeological finds, came into the possession of the competent authorities. Since 2002 it has been in the possession of the regional museum of prehistory in Halle, Saxony-Anhalt, where it has been on permanent display since 2008.
In-depth scientific investigations were subsequently conducted on the site of the discovery. Studies have not yet clarified whether the stone cavity within which the disk was found is an ancient stronghold or a burial chamber. The place, the top of the Mittelberg, when the mountain had not yet been covered by high vegetation, may have been used in the Neolithic, probably as an astronomical observatory. The site is located approximately 20 kilometers from the Goseck Solar Observatory.
The Goseck site consists of a circle with a diameter of 75 meters, originally composed of a hill surrounded by a series of four concentric rings, a ditch and, all around, two palisades made with wooden poles the height of a man. The interpretation of the Goseck site as an archaeoastronomical observatory takes on particular importance, because it is the backdrop to the discovery of the Nebra disk.
Description and interpretation of the symbols on the Nebra Sky Disk
The Nebra disk was mainly examined by the archaeologist Harald Meller (Institute for Archeology and Preservation of Historic Monuments Halle), the astronomer Wolfhard Schlosser (University of Bochum) and the archaeological chemists Ernst Pernicka (archaeometallurgy), Heinrich Wunderlich (construction technique and method) and by Miranda J. Aldhouse Green (University of Wales), archaeologist and scholar of Bronze Age religions.
According to their interpretations, the smaller circular plates represent the stars. Among them stands out a small group of seven closer together plates which represent the Pleiades, a star cluster visible to the naked eye in the constellation of Taurus.
The two largest disks, the circular one and the sickle-shaped one, respectively represent the Sun (but it could also be the full Moon) and the crescent Moon.
The curved lines set on the edges of the disk must have represented portions of the horizon visible from the site where the artifact was found.
This interpretation is supported by the fact that they cover an angle of 82°, which is precisely the angular difference between the points of rising and setting of the Sun on the horizon, at the latitude of the place of discovery, in the periods between the summer solstices and in winter.
On the edge of the disk there is a golden arch reminiscent of a sailing boat on the sea, interpreted as the "Boat of the Sun". The small indentations along each side of the arch may represent the ship's oars. Many ancient peoples imagined the Sun traveling from east to west on board a special ship.
According to archaeologist Miranda Aldhouse Green, the disc contains the symbols of a deeply religious theme such as the sun, the horizon for the solstices, the boat of the sun, the moon and other particular examples of stars: the Pleiades. The creators certainly wanted to group together all the other cult symbols that had also come to light in different European regions; it is therefore part of a complex religious system widespread throughout Europe; perhaps it indicates a religious message.
Finally, 40 holes of approximately 3 mm are impressed with extreme precision on the edge of the disc. The purpose of the side holes is unclear; they probably served to fix it, which suggests that the disk was also used as a cult object.
If the disk was intended as an astronomical instrument, the only thing that is accurate is the pair of arcs. By placing the disk on a horizontal plane, it could have been used to examine the position of sunrise and sunset. Alternatively, the disc could have been a teaching tool, intended to reveal the mysteries of the night sky to groups of initiates, perhaps future shamans.
In any case, the Nebra disk represents a unique artifact of its kind, capable of establishing with certainty that the so-called primitive peoples had an advanced knowledge of the heavens. Unlike sites such as Newgrange (3200 BC) and Stonehenge (2000 BC), the Nebra disk is the first portable astronomical almanac in human history and demonstrates that knowledge of the heavens was not limited to British populations alone, but was widespread throughout Europe of the second millennium BC.
