Science journalist and author Jo Marchant discussed the century-long quest to understand the origin and purpose of a Greek artifact known as the Antikythera mechanism. The object was initially recovered in 1900, when a group of sponge divers stumbled upon an ancient shipwreck in the Mediterranean. According to Marchant, the wreck proved to be a treasure trove of Greek antiquity but the Antikythera mechanism, corroded and encrusted in sea growth, was overlooked. About a year later, in 1901, the rock-like crust cracked open and historians realized they had something special, she said.

The 2000-year-old device was extremely sophisticated, Marchant explained, noting that it was covered with highly-detailed inscriptions and composed of dozens of gear wheels that could be operated by a single dial on the side. Besides the Antikythera, Marchant pointed out that there are no other artifacts with gear wheels from the ancient world. In fact, there is no technology as sophisticated and compact as this mechanism until around the 17th century, she added.

Researchers eventually concluded that the device was a 'calendar computer,' Marchant said, capable of accurately predicting the movement of the Sun, Moon, and the five planets known to ancient Greek astronomers. It also functioned as a 19-year calendar based on the lunar cycle, showed the location of the Greek games every four years, and had an eclipse indicator, Marchant noted. She suggested the Antikythera mechanism was likely built for a wealthy lay person and may have been used as a philosophical/religious demonstration of the workings of the heavens.