Desert Skies: The Birth of Arabian Astronomy

Embers from a campfire dance upwards into the night sky, joining the myriad of stars that pin-prick the darkness above the desert of AlUla. For thousands of years, desert dwellers and travellers have lain on the sands and stared up at the stars with wonder—captivated by their beauty and their mystery.  And so, the science of astronomy became a part of Arabia.

With little light pollution or cloud-forming moisture, the desert has always offered an uninterrupted view of the infinity of space, making it easy to study celestial phenomena from the dramatic passage of comets to the curious movement of the stars. And this knowledge influenced early Arabian society. Archaeoastronomy is exploring how civilisations like the Nabataeans incorporated the heavens into their worldview: it’s likely that their majestic tombs were not only conscientiously carved but also consciously aligned with the rising and setting of certain stars.

Unravelling the mystery is not as simple as it seems because the Earth’s wobble, the precession of the equinoxes, has shifted the stars over the centuries. 2,000 years ago, the skies above AlUla looked a little different, notably the absence of a north star. Instead, the Bedouin found north through a trio of stars that danced around the North Celestial Pole. But by carefully tracking the position of these and other stars, they could confidently find their way across the vast expanses of desert.

With sleeping beneath this blanket of stars came a close connection. As well as naming the constellations, the Bedouin told fantastic stories to explain their place and passage in the night sky. One of the brightest stars was a brilliant red supergiant that they called ad-dabaran, Aldebaran, the Follower. The tale goes that Pleiades, called ath-Thurayya or simply ‘the Star’ because of its prominence, was in love with the Follower. But al-‘ayyuq, the Impeder, lived up to its name and prevented the lovers from coming together. To this day, the Impeder watches the Follower chase ath-Thurayya across the sky, forever unable to catch her.

Such romantic tales have endured through the ages and are still told today. But despite their fanciful appeal, they are rooted in the careful celestial observation for which Arabia became famous. The Islamic tradition of scholarship combined with a need to predict lunar cycles, time, and location for religious practices made astronomy a celebrated field of study. Translating and then correcting and expanding the works of influential astronomers from Persia, India, and Greece, while merging them with traditional Bedouin observations, Islamic astronomers mapped the stars and their movements with exceptional accuracy—modelling the universe.

The knowledge they developed led the world: Islamic astronomers proposed that the Earth revolved around the sun five centuries before Galileo suggested the same. They calculated the diameter of the Earth, measured the thickness of the atmosphere, and proposed that the Earth rotated on its own axis, making a host of significant scientific breakthroughs on which later astronomers would build. And their legacy lives on in the names of the stars.

Today, more than 200 of the brightest stars in the sky have Arabic names, among them Fomalhaut meaning ‘mouth of the whale’; Achernar meaning ‘end of the river’; and Deneb meaning ‘tail of the fowl’ because of its prominent position within the Greek constellation of Cygnus, meaning swan. The night sky we can see is written in Arabic. And lying on the desert sands of AlUla, it’s easy to see why. The thousands of stars that light up the desert both inspire wonder and invite inquiry, connecting every stargazer not only to the wonders of the universe, but to the people who have been unravelling its secrets for millennia.