An astrolabe – Greek for ‘star finder’ – is an instrument with over 2,000 years of history. They could be incredibly intricate, and were used to help keep time, navigate and cast horoscopes. Curator William Greenwood looks at an example from the Islamic world, and explains how you’d go about using one. | British Museum

Here's how to read an ancient astrolabe: | NOVA l PBS

Astrolabe: A Brief History and Its Significance The astrolabe is an ancient astronomical instrument that served multiple purposes, including: Measuring the altitude and position of celestial bodies relative to the horizon. Determining latitude and local time. Creating celestial maps. Predicting astronomical events, such as eclipses and planetary conjunctions. The origin of the astrolabe is uncertain, but it is believed to have been invented in ancient Greece around the 2nd century BC. The earlie