The oldest known astrolabe was used on one of Vasco da Gama’s ships
The navigational device dates back to as early as 1496
![astrolabe](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2019/03/031819_bb_astrolabe_feat.jpg?fit=860%2C460&ssl=1)
MARINER’S FRIEND A metal disk found at a shipwreck site near Oman is the oldest known mariner’s astrolabe, a device for navigating at sea.
D. Mearns