The 11th century astronomical text Kayhān Shinākht (“Knowledge of the Cosmos”) was written in Central Asia by the noted polymath Qaṭṭān al-Marwazī (1072/1073 – 1153 CE). Like other pre-eminent scholars of his era Marwazī produced works on literature, medicine, engineering, and astronomy, all of which, with the exception of Kayhān Shinākht, appear to have been lost. Surviving in a single manuscript copy, this work is remarkable for having an extant Arabic translation of the original Persian, as well. The only known witness of the Arabic text is an incomplete manuscript dating from the 19th century, and one which, judging from the script, was produced in North Africa. The presence of this rare technical work, written in Persian and subsequently translated into Arabic, raises questions about the transmission of scientific knowledge across the Islamic world. Why was an Arabic translation of this rather elementary Persian text deemed desirable in the first place? Where, when, and by whom was the translation carried out? How did this work find its way so far from its place of origin? Which features in the work recommended it as a text suitable for copying as late as the 19th century? Evidence from the texts themselves is used to explore these questions. The Arabic text is characterized by a remarkable fidelity to the original. The discrepancies that can be observed between the two texts appear to stem in part from their individual transmission histories, in addition to a recognition by their creator(s) of the need to tailor the text to a specific audience. Taken together the two works highlight the remarkable instance of the transmission of scientific knowledge across periods, cultures, and locales.