Mariner's Astrolabe from 1503 Shipwreck Inducted into Guinness World Records as World's Oldest

The astrolabe is of between 1496 and 1501 sunk to the bottom of the sea with a shipwreck in 1503 near the coast of the island of Al-Ḥallānīyah, which is now Oman. It is one of only 104 historical astrolabes in existence.

David Mearns, an oceanographer at Blue Water Recovery, said in a 2017 statement after it was first analyzed that it is a privilege to find something so rare and so historically important. He led the archaeological excavation of the wreck.

A Maritime Disaster

Mariner's astrolabe is a circular device that sailors used to measure the altitude of the sun or stars that allowed them to calculate their ship's latitude. This instrument just inducted into the Guinness World Records was discovered under a layer of sand in the Arabian Sea in 2014. It went down with a ship under the command of a Portuguese commander named Vicente Sodré, who was the uncle of the famous explorer Vasco da Gama.

Sodré and his brother, Brás Sodré, were commanding a subfleet of 5 ships in the 4th Portuguese India Armada in 1503. They were supposed to be patrolling off southwestern India, protecting a couple of trading outposts. But, they headed to the Gulf of Aden, where they looted several Arab ships and then headed to Al-Ḥallānīyah. In May 1503, an enormous wind blew, smashing two of the ships, the Esmeralda and the Sâo Pedro, into the rocks of the island.

In 1998, archaeologists surveyed the area and found what looked to be a wreck site. It was not until 2013, however, that the Oman government and researchers could arrange an excavation in the remote area. Over the next 2 years, archaeologists recovered almost 3,000 artifacts from the site that includes a ship's bell inscribed with the year 1498.

Navigation by the Stars

It measures 6.9 inches in diameter and is festooned with the Portuguese coat of arms and an armillary sphere. The metal used is an alloy made mostly of copper, with a little zinc, tin and lead.

To uncover the markings researchers at the University of Warwick in England used laser scanning to detect the grooves and etchings. The results revealed 18 scale marks on the upper right of the disk that would have allowed the navigator to measure the angle of the sun or stars.

By: Aishwarya Sharma

Content: https://www.livescience.com/65032-oldest-mariners-astrolabe.html