Earliest known marine navigation tool revealed with scanning technology

Details on earliest known marine navigation tool revealed by scanning technology at WMG, University of Warwick. Late fifteenth-century astrolabe - used by mariners to measure the altitude of the sun - recovered from Portuguese explorer ship which sank in 1503 Pioneering scanning analysis and 3D imaging revealed invisible navigational markings, proving the identity of the object Details of the earliest known marine navigation tool, discovered in a shipwreck, have been revealed thanks to state-of-the-art scanning technology at WMG, University of Warwick. Professor Mark Williams from WMG was tasked with scanning the artefact - an astrolabe from the late fifteenth century, used by mariners to measure the altitude of the sun during voyages - which was excavated in 2014 by Blue Water Recovery. When the team found the object, no markings were visible - they believed it was an astrolabe , but they could not see any navigational markings on it. They then approached Professor Williams, who conducts pioneering scanning analyses in his laboratory at WMG, to reveal the artefact's invisible details. The scans showed etches around the edge of the object, each separated by five degrees - proving that it is an astrolabe . These markings would have allowed mariners to measure the height of the sun above the horizon at noon to determine their location so they could find their way on the high seas.