The book provides a personal and engaging account of the author's role in the reclassification of Pluto from a planet to a dwarf planet. Through a blend of memoir and scientific exploration, the author recounts the discovery of Eris, a celestial body larger than Pluto, which sparked a debate within the astronomical community about the definition of a planet. The narrative delves into the challenges and excitement of astronomical discoveries, the intricacies of scientific classification, and the eventual decision by the International Astronomical Union to redefine what constitutes a planet, ultimately leading to Pluto's demotion.
