What is an astrolabe used for?

An astrolabe is an ancient astronomical instrument primarily used for solving problems related to time and the position of celestial bodies. Its primary function in navigation is to calculate latitude, which is the measurement of a location's distance north or south of the equator. By measuring the angle of stars above the horizon, navigators could determine their latitude while at sea, aiding in maritime exploration and navigation. This capability was particularly important before the development of more advanced navigational tools.

While other instruments and methods were used to measure speed, map stars, or determine longitude, these tasks do not align with the unique purpose of the astrolabe. Longitude determination, for example, required different methodologies, such as accurate timekeeping, which was a significant challenge until later advancements. Thus, the astrolabe's role in calculating latitude makes it a crucial tool in historical navigation practices.