When the American Museum of Natural History’s Hayden Planetarium stopped calling Pluto a planet, director Neil deGrasse Tyson found himself at the center of a firestorm led by angry Pluto-loving elementary school students. What is it about Pluto – a cold, distant, icy rock – that captures so many hearts?

In August 2006, the International Astronomical Union voted Pluto out of planethood. Far from the sun, tiny, and eccentric in orbit, it’s a wonder Pluto has any fans. Yet during the mounting debate over Pluto’s status, Americans rallied behind the extraterrestrial underdog.

Only Tyson can tell this story: he was involved in the first exhibits to demote Pluto, and, consequently, Pluto lovers have freely shared their opinions with him, including endless hate mail from third graders. In his typically witty way, Tyson explores the history of planet classification and America’s obsession with the “planet” that’s recently been judged a dwarf.