When a strange stone pillar is discovered at the Hong Kong Observatory, young astronomer Cen and his two assistants are assigned to investigate. Their search through old records and modern instruments uncovers an astonishing truth: the pillar isn't just a relic—it's an ancient astronomical device hiding a 150-year-old mystery! Blending science, history, and adventure, CMS Astronomical Explorers launches readers into a cosmic puzzle where curiosity is the key to discovery.