Of all the giants on whose shoulders we stand, Aristarchos of Samos, the ancient Greek all-rounder, has proved especially tall: no one else (not even Einstein, to mention an iconic figure) has ever discovered anything (of like importance) that took so long to dawn on the rest of humanity. His achievement was indeed extraordinary: with the technological means available in his time (namely, the naked eye and a genius mind), he got to know the sun's distance better than anyone else before, putting the earth in motion around the sun for the first time in human awareness. The present book examines what history has spared of him and invites the reader to relive astronomy's greatest moment.