The Antikythera Mechanism: Unraveling the Secrets of an Ancient Greek Shipwreck

The Antikythera wreck is a sunken Greek cargo ship lying off the coast of a tiny island at the western edge of the Aegean Sea. Dated to approximately 60 BCE, it is the largest ancient shipwreck ever discovered and is noted, above all, for the highly sophisticated analog computer that was recovered from its debris.

A piece of the Antikythera mechanism discovered in 1901, dating to 205 BCE. Currently located in the National Archaeological Museum, Athens, Greece (Fine Art Images/Heritage Images/Getty Images)

Antikythera lies about 21 miles off the northwestern tip of Crete, and is on the most direct route between the Aegean and the western Mediterranean seas. Investigators believe that the ship, which appears to have been about 130 feet long, was on its way from a Greek port in the Aegean to Italy and that it may have been wrecked during a gale. Its debris is scattered at a steep angle on the sea floor off the eastern side of the island, approximately 180 feet below the surface and near a series of underwater cliffs.

The wreck was discovered in the spring of 1900 by Greek sponge divers, one of whom wore a helmet and a diving suit and breathed air pumped down a hose in order to retrieve the arm of a bronze statue from the seabed. Subsequently the group’s captain reported the find to Greek authorities, who paid the men to return to the site and sent navy ships to join in its exploration. The following year the group managed to bring up a number of artifacts, including pieces of what would become known as the Antikythera mechanism. However, two of the divers were injured in the process and another died from the “bends,” or decompression sickness.

An expedition led by famed underwater explorer Jacques Cousteau (1910-97) visited Antikythera aboard the ship Calypso in 1953, surveying the sea floor and identifying what appeared to be another wreck 500 feet south of the main site. Cousteau returned to Greece in 1976 to film a series of documentaries, including one devoted to the Antikythera wreck.

As before, the wreck’s depth prevented Cousteau and his fellow divers from working on the seabed for extended periods, even though they were equipped with SCUBA (self-contained underwater breathing apparatus) gear. Nevertheless, they retrieved some 300 additional artifacts. Cousteau’s 1978 documentary Diving for Roman Plunder introduced the subject of the wreck to a wide audience.

In 2012, the Woods Hole Oceanographic Institution of Massachusetts, the Greek Navy, and Greece’s Ephorate of Underwater Antiquities began mapping the 2.6-acre site and searching for additional artifacts. The project was supported with research grants from individuals and institutions around the world and received the use of a yacht, a helicopter, and an aluminum-alloy Exosuit, allowing divers to work at depths of as much as 1,000 feet. Developed by Nuytco Research, the invention maintains pressure at 1 atmosphere (the pressure at the Earth’s surface), making it possible for divers to surface quickly without the danger of decompression sickness.

Artifacts recovered from the Antikythera wreck include bronze and marble sculptures as well as numerous coins and pieces of glassware and jewelry. One of the most striking finds is a life-sized bronze statue known as The Antikythera Youth. The artifacts can be traced to various locations throughout the eastern Mediterranean world, including Asia Minor and Egypt, and are now housed in the National Archaeological Museum in Athens. Fragments of human skeletons have also been brought up from the site, including well-preserved teeth and pieces of a skull found in 2016. There are hopes that DNA analysis of tissue from these recent finds may reveal details about the individual’s origins.

What to Do with the Artifacts from Shipwrecks? Did you know that it is estimated that there are more historical objects on the bottom of the ocean than there are in all the world’s museums combined? Yet these artifacts are under a constant threat of looting and underwater tourism. Fortunately, in 2001 the United Nations Educational, Scientific, and Cultural Organization (UNESCO) issued a Convention on the Protection of Underwater Heritage. Artifacts, sites, or shipwrecks that have been underwater for at least 100 years now qualify for protection, and underwater archaeologists welcome the chance to preserve sites such as the Titanic. The same underwater archaeologists, however, generally concur that if a site or shipwreck is threatened by the elements, the artifacts should be recovered. Christopher MacMahon and Rainer F. Buschmann

The most remarkable artifacts from the wreck are the pieces of the Antikythera mechanism, an ancient Greek computer whose extraordinarily sophisticated nature was not determined by investigators for decades. Designed to replicate the apparent motions of the sun, Earth’s moon, and the five extraterrestrial planets known to the ancients, it was also capable of predicting the phases of the moon, the rising and setting of prominent stars, and lunar and solar eclipses. Scientists believe that the mechanism was already old at the time of the shipwreck and that it may have been built as early as 205 BCE. The pieces discovered in 1901 represent less than half the mechanism, but by the end of the 2016 search effort, no more had been found. Grove Koger.

FURTHER READING:Harris, Mark. 2014. “Into the Deep.” New Scientist (June 7): 19-20. Hilts, Philip J. 2015. “In Search of Sunken Treasure.” Scientific American (January): 68-75. Jones, Alexander. 2017. A Portable Cosmos: Revealing the Antikythera Mechanism, Scientific Wonder of the Ancient World. New York: Oxford University Press.

Marchant, Jo. 2015. “Exploring the Titanic of the Ancient World.” Smithsonian (February.): 56-69.