New research suggests that Nicolaus Copernicus’s heliocentric model of the solar system may have been significantly influenced by the work of a 14th-century Muslim astronomer, Ibn al-Shatir. The study draws detailed comparisons between the planetary models of both figures and proposes that Copernicus’s ideas could have stemmed—directly or indirectly—from earlier Islamic scientific traditions.

Copernicus, the renowned 16th-century Polish astronomer, is widely credited with initiating the so-called Copernican Revolution by proposing that the Sun, not the Earth, lay at the centre of the universe. His work challenged the prevailing geocentric models derived from Aristotle and Ptolemy and helped lay the foundation for modern astronomy.

But according to a recently completed PhD thesis by Dr. Salama Al-Mansouri of the University of Sharjah, Copernicus’s model bears a remarkable resemblance to one developed nearly 200 years earlier by Ibn al-Shatir, a Damascene astronomer who served as the timekeeper of the Umayyad Mosque.

“Ibn al-Shatir was the first astronomer to have successfully challenged the Ptolemaic cosmological system of planets revolving around Earth and corrected the theory’s inaccuracies about two centuries before Copernicus,” says Dr. Al-Mansouri. Her study, now available through the Sharjah University Library, offers a critical textual analysis of the two astronomers’ work, focusing in particular on Copernicus’s De revolutionibus orbium coelestium (On the Revolutions of the Celestial Spheres) and Ibn al-Shatir’s treatise Nihāyat al-Sul fī Taṣḥīḥ al-Uṣūl (The Final Quest Concerning the Rectification of Principles).

The research reveals “compelling correlations,” especially in the mathematical models used to represent planetary motion. According to the study, “Ibn al-Shatir’s astronomical manuscripts, particularly his work in Nihāyat al-Sul, demonstrate planetary models that predate and closely mirror those later proposed by Copernicus, indicating a shared mathematical lineage,” says Mesut Idriz, professor of history and Islamic civilization at the University of Sharjah and one of the study’s supervisors.

Despite these similarities, the study acknowledges that Ibn al-Shatir remained within a geocentric paradigm. However, Dr. Al-Mansouri argues that the precision of his refinements made them readily compatible with Copernicus’s heliocentric reinterpretation. “Our analysis reveals that Ibn al-Shatir’s treatise, though geocentric in intent, produced results so aligned with heliocentrism that Copernicus’s debt to him is undeniable—two centuries of separation could not erase this intellectual kinship.”

But how might Copernicus have encountered these ideas? Dr. Al-Mansouri surveyed Arabic manuscripts and their Latin translations preserved in European archives—including those in Kraków and the Vatican—where Copernicus studied and developed his astronomical theories. She reports that Nihāyat al-Sul was among the materials archived there in its original Arabic. “Though in its original Arabic version, the manuscript could not have escaped the attention of a scholar like Copernicus,” she writes.