COSMOPOET aims to rethink the relationship between poetry and astronomy and ultimately, it investigates medieval Greek solutions to the question as to how to explain the cosmos through literary means. This is a project about the interaction of science and literature and about interpreting scientific literature as literature in the context of the intellectual space of the Byzantine schools and the multiple curricula coexisting at the higher educational level. COSMOPOET studies the medieval Greek and early modern manuscript tradition of the didactic poem ""Phaenomena"" by Aratus of Soli (d. before 239 BCE) and compares it to transmission of the introductory astronomical treatise ""The Heavens"" by Cleomedes (first century CE). Both texts introduce the reader-student to elementary cosmology and astronomy and prompted the production of commentaries of textual and of diagrammatic nature, as their popularity in Byzantium increased from the late thirteenth century onwards. COSMOPOET studies 1) the textual dimension of both discourses (especially the didactic use of formal literary features such as verse and rhythm); 2) their respective graphic features (e.g. layout and diagrams); 3) the associated paratexts (e.g. epigrams, scholia, marginal and interlinear annotations) and 4) standalone commentaries, and 5) how they change as evidenced in manuscripts copied from the tenth to the sixteenth century. Thus, COSMOPOET formulates and tests the hypothesis that the examination of both paratexts and graphic features of scientific discourse, and of their respective variations through time can answer questions concerning the practices of teaching and learning cosmology and elementary astronomy in Byzantine advanced education.