Final answer:
The astrolabe was a historical navigational tool for measuring the angles of celestial bodies, improving maritime navigation but later replaced by the sextant due to its limitations. Improved upon by Islamic scientists and European scholars, its invention is often attributed to ancient Greek astronomers.
Step-by-step explanation:
The astrolabe was a versatile navigational instrument in the past, chiefly used for determining the angle of celestial bodies (sun, moon, and stars) above the horizon. This enabled navigators to determine the time of day, along with sunrise and sunset times. The exact origins of the astrolabe are not definitively known, with various early versions existing in different cultures. However, it is widely recognized that ancient Greeks, and in particular Hipparchus, made significant contributions to its development. The tool was further refined during the Islamic Golden Age by scientists like Al-Sufi and later improved in the medieval period by figures such as Johannes Stöffler.
In the context of navigational technology, the astrolabe was succeeded by more sophisticated instruments like the sextant and the cross-staff, which offered improvements in accuracy under rough sea conditions. Astrologically, it was also used by Persian mystics and other scholars for making astrological predictions based on the stars.