Astrolabe

astronomy · ancient tools · navigation · science

Ancient star mapper. An astrolabe is a flat metal disc covered with wires, cutouts, and holes that works like a portable sky map. Sailors and astronomers used it for thousands of years to find and identify stars and planets in the night sky.

Measures celestial heights. You can hold an astrolabe up to the sky and use it to measure how high a star or planet sits above the horizon. This helped people figure out where they were on Earth and navigate across oceans.

Built-in calculator. The astrolabe is really a mechanical computer made of metal. Its carefully arranged circles and lines let you solve difficult astronomy problems by lining things up and reading off answers.

Travel companion. Explorers and ship captains carried astrolabes on their voyages to find their exact location and plan their routes. It was one of the most important tools for age of exploration and discovery.

Timeless invention. People in the Islamic Golden Age, Byzantine Empire, medieval Europe, and ancient Greece all used astrolabes. This incredible tool stayed useful for over 2,000 years.