How I Killed Pluto and Why It Had It Coming is the title of the memoir by Mike Brown

Michael E. Brown

Michael E. Brown has been a professor of planetary astronomy at the California Institute of Technology since 2003....

, the Caltech astronomer

Astronomer

An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...

 most responsible for the eventual demotion of the planet Pluto

Pluto

Pluto, formal designation 134340 Pluto, is the second-most-massive known dwarf planet in the Solar System and the tenth-most-massive body observed directly orbiting the Sun...

 from its status of a planet to that of a dwarf object.

Summary

The memoir is a non-fiction account of the events surrounding the eventual demotion of Pluto from full-planetary status. It chronicles the discovery of Eris

Eris (dwarf planet)

Eris, formal designation 136199 Eris, is the most massive known dwarf planet in the Solar System and the ninth most massive body known to orbit the Sun directly...

, a dwarf planet even larger than Pluto, located within the Kuiper belt

Kuiper belt

The Kuiper belt , sometimes called the Edgeworth–Kuiper belt, is a region of the Solar System beyond the planets extending from the orbit of Neptune to approximately 50 AU from the Sun. It is similar to the asteroid belt, although it is far larger—20 times as wide and 20 to 200 times as massive...

, beyond Neptune's orbit. The replaying of events include the adversarial challenging of long-held scientific beliefs between some of the world's leading astronomers, and the eventual 2006 International Astronomical Union

International Astronomical Union

The International Astronomical Union IAU is a collection of professional astronomers, at the Ph.D. level and beyond, active in professional research and education in astronomy...

's vote to demote Pluto from the nine planets of the Solar System.

Reviews

Reviews of the book have been generally positive, with James Kennedy of the Wall Street Journal calling the book a "brisk" and "enjoyable ... chronicle" of the tale of the search for new planets and the eventual resulting demotion of Pluto from planetary status. Janet Maslin of the New York Times called it a "short, eager-to-please research memoir".