What is an Astrolabe?

Ancient navigation

The Turks and Caicos National Museum’s logo is the astrolabe, a navigational instrument used during the Age of Discovery to determine latitude.

astrolabe|84An astrolabe is a circle with degrees marked around the perimeter and a pivoting arm mounted in the center. By aligning the arm with the celestial body and the zero point of the circle with the horizon, the navigator measured the angle between a celestial body and the horizon. He then consulted astronomical tables to detemine his latitude.

Using the astrolabe allowed navigators to calculate their latitude—that is, their north-south position. However, they were not able to calculate their longitude or east-west position until the invention of the chronometer in the1730s. The inability to determine an exact longitudinal position caused many shipwrecks.

With the astrolabe, a mariner could determine where he was, where he’d been, where he was going. The Astrolabe, the Museum’s quarterly newsletter, is our means of letting the public know what we are doing, what we’ve done, and what we plan to do.