Volvelle for the position of the Moon from the Organum Uranicum by Sebastian Muenster, 1536.

Construction of a radio telescope at Owens Valley Radio Observatory.

A Persian astrolabe from 1221 or 1222. It is the oldest functioning geared astronomical instrument.

Figure from Textus de Sphera by Johannes de Sacrobosco, 1507.

Depicts Urania, the muse of astronomy, Astronomy, and Ptolemy under a celestial sphere.

Fragment of the Antikythera mechanism, a Greek celestial clock, built in the 2nd century BC.

This is the largest gear in the system. It would have been covered by a panel on the front that indicated the position of the Sun, Moon, and probably the five planets.

The Newgrange monument, constructed in the 4th millennium BC. The entrance passage is aligned towards the position of sunrise on the winter solstice. However, because the passage curves down, sunlight from the entrance cannot reach the central chamber.

Interior of an Egyptian water clock during the reign of Amenhotep III (c. 1300s BC).

Each column of dots is a set of hour markers at different months of the year. Because each night was always 12 hours long, the length of an hour changed over the course of a year.

Babylonian cuneiform tablet enumerating the longitude of Saturn at successive occurrences of first visibility, stationary points, and disappearance, computed using System A.

For the past few years I've been producing a podcast about the history of astronomy called the Song of Urania. I just wrapped up the first two seasons which cover ancient astronomy and non-Western astronomy.

Check it out here: songofurania.com