When was the astrolabe invented?

The astrolabe was invented around 200 B.C. in classical Greece. The invention of this ancient tool is often credited to the Greek astronomer Hipparchus, born in Nicaea, which was in Asia Minor.

An astrolabe was a tool that used time and the position of the sun and stars in solving problems. It was often used to determine the positions of cosmic bodies at a specific time and when viewed from a certain place.

Along with astronomy, astrolabes were regularly used in geography, timekeeping and surveying. It also aided in navigation.