In 2005 Mike Brown discovered Eris which was slightly larger than Pluto. This discovery sparked a series of international debates resulting in the demotion of Pluto to a dwarf planet. Brown recounts his controversial discovery in this part memoir and part planetary saga in How I Killed Pluto and Why It Had It Coming.
Barrie W. Jones' Pluto: Sentinel of the Outer Solar System delves into discussions of scientific discovery as well as an exact account on Pluto, its satellites and its controversial re-classification.

Pluto was discovered by astronomer Clyde Tombaugh at the Lowell Observatory at Flagstaff, AZ, on February 18, 1930. It was considered the 9th planet of the solar system until August 24, 2006, when astronomers reclassified it as a dwarf planet.