Almagest

Almagest is a scientific treatise by Ptolemy, the Greek astronomer, written in Ancient Greek and first published in 148. It belongs to the world of mathematics and astronomy, and it focuses on how the stars and planets appear to move. The book lays out a geocentric view of the universe in a structured, technical way, with explanations meant to describe the sky as carefully and systematically as possible for its time.

This is a good fit for readers interested in the history of science, ancient astronomy, and the long life of early scientific ideas. It is not light reading, but it is clear in purpose and important as a source for Greek astronomy. If you enjoy classic nonfiction that sits between science, philosophy, and observation, this book connects naturally with works in the same scholarly tradition and with the broader history of astronomical thought.