Observatory of Ulugh Beg, Samarkand – A Place Where History and Science Meet

The museum of Ulugh Beg Observatory

photography by: Omri Westmark

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During the 15th century, Samarkand was among Asia’s most important cities, serving as the vibrant capital of the Timurid Empire, as well as a major cultural and economic hub along the Silk Road. Perhaps one of the most profound testimonies for its global significance can be found atop a small hill on the city’s northeastern fringes. Once the leading astronomical center in the entire world, the Ulugh Beg Observatory (or what remains of it) offers a glimpse of the city’s bygone era, when it was at the forefront of scientific and technological progress.

Nestled in modern-day Uzbekistan, Samarkand is Central Asia’s most iconic city, boasting myriads of Islamic-style landmarks to awe at. Despite its undisputed monumentality, the city’s golden age is long gone, as a couple of centuries ago, it was considered a global center of science and innovation.


In 1411, Ulugh Beg, the grandson of Timur (aka Tamerlane) assumed control over his grandfather’s empire which stretched across vast swaths of land in Central Asia, the Middle East and the Caucasus. In stark contrast to his predecessors, Ulugh Beg showed far more interest in astronomy and mathematics rather than military campaigns.


In fact, it was during his reign that dozens of well-known astronomers were invited to partake in the construction of what would become the most cutting-edge astronomical institution of its time. Erected in 1422, in the northern outskirts of Samarkand, Ulugh Beg Observatory was a 3-story cylindrical building with a diameter of 42 meters.


The observatory’s centerpiece was a quadrant device, better known as the Fakhrī sextant. Originally stood at a height of about 40 meters, the instrument was used to measure the angle between the zenith and a celestial body, thus determining its altitude. Using this arch, Beg and his fellow cosmologists not only managed to successfully confirm the Earth’s axial tilt as 23.5 degrees, but also determined that a length of a single year is 365 days, 5 hours, 49 minutes and 15 seconds, merely 30 seconds shy of the actual datum, a remarkable accomplishment given the then level of technology.


Since the observatory was built of soft bricks, its height was restricted to a measly 30 meters. In order to install the massive quadrant within the confines of the edifice, a deep trench was curved out of the rock beneath. The meridian arc was then neatly fit into the pit, where it was also less prone to seismic interferences.


In spite of his multiple scientific achievements, Ulugh Beg’s cling to power came into an abrupt end in 1449, when his eldest son, Abdal-Latif Mirza, rebelled against him, and subsequently, order his assassination as he was on his way to make the pilgrimage to Mecca. Shortly thereafter, Beg’s lifetime project, his famed observatory, was reduced to rubble, cutting short years of scientific breakthroughs.


For centuries on end, the once world-renowned complex was left in tatters, buried under meters of rock and soil. It wasn’t until 1908, when Russian archaeologist Vassily Vyatkin unearthed the remnants of the observatory. As of today, the only vestige of the original building is the sextant’s underground section, which since then has been embellished with an ornate Iwan.


The nearby Ulug Beg Observatory Museum offers tidbits of info about its protagonist’s work and achievements, including a reproduction of Zīj-i Sultānī, a catalogue where over 1,000 stars are thoroughly mapped with a sheer accuracy, far ahead of its time.