16th century illustration showing a diagram of an astrolabe centred at 48 degrees from a German manuscript published in Munich or Vienna and later transferred to Nuremberg. An astrolabe is an ancient astronomical instrument that served many functions including surveying, and predicting the positions of stars, planets, the sun, and the moon. Illustration from a manuscript dating from around 1500-1510 made in either Munich or Vienna and later moved to Nuremberg, Germany.