How I Killed Pluto and Why It Had It Coming by Mike Brown, the guy who discovered Eris. He's a very good popular science writer, and I really hope he writes more and regularly. It's amazing the skulduggery that can happen even in a hard science when it's humans doing it.

It's also a useful life lesson in the value of hard bloody work: do you know how he discovered Eris, Sedna, Makemake and Haumea? Not one but two surveys of large percentages of the sky, over two years (the first time) and four months (the second time). It's quite hard work looking somewhere no-one's looked before or to that depth.