Ulugbek Observatory

The observatory’s core featured a gigantic goniometer (a vertical circle), with a radius of 40.212 meters and an arc length of 63 meters. The primary instrument, a sextant, was aligned with extraordinary accuracy along the meridian from south to north, a feat confirmed by the findings of modern astronomers like Kastalsk and Sheglov. The meticulous construction, combined with Ulugbek’s scientific acumen and that of his colleagues, resulted in astoundingly precise astronomical observations.

The Samarkand astronomers’ accuracy is particularly remarkable given that their observations were conducted without optical aids, relying solely on the naked eye. Their astronomical tables listed the coordinates of 1,018 stars. Ulugbek’s catalog remains invaluable even today, with his calculation of the length of the sidereal year being astonishingly close to modern measurements. Ulugbek estimated the year to be 365 days, 6 hours, 10 minutes, and 8 seconds, while contemporary data places it at 365 days, 6 hours, 9 minutes, and 9.6 seconds—a negligible discrepancy of less than a minute.

Tragically, following Ulugbek’s demise, the observatory fell victim to destruction and looting by religious zealots. It wasn’t until 1908 that the archaeologist Vyatkin discovered the first document indicating the observatory’s location. Regrettably, only the underground portion of the sextant and the foundation of the building survived. Utilizing these findings, scientists were able to reconstruct a model of the observatory.

The obliteration of this remarkable scientific hub, the plundering of its invaluable library, and the expulsion of its scholars marked a dark chapter in history. The local priesthood, in an attempt to erase the memory of Ulugbek’s beacon of science, declared the hill a sacred site for the «Forty Virgins» and erected a mausoleum there, turning it into a lucrative pilgrimage site. Thus, the Samarkand clergy sought to extinguish the legacy of Ulugbek and his observatory, a legacy that had once illuminated the path of knowledge and discovery.