Why I read it: Took some astronomy in college and toyed with majoring in it.
Summary: The discovery of one, perhaps two new planets, based on the old definition of "wanderer" of the night sky, as described by the ancient Greeks, brought the whole question of that definition into question. Mike Brown, one of the discoverers of those new bodies, gives his first hand account of how Pluto went from member of the family to outcast because of his own work.
My Thoughts: I took some astronomy at UMASS Amherst, and had a blast doing so. The hardest part for me was the numbers. They just made no sense. I could grasp distance when someone told me it was 100 miles between the college and my home; I ddin't get the 93,000,000 miles between the earth and the sun. All I knew was I'd never make it to the sun on a single tank of gas.
That said, neither siderophobes nor numerophobes need fear this book. Mike Brown understands that the general public is not fluent in the special language reserved for astronomers and physicists and does a wonderful job of keeping the book flowing even through some necessarily inserted large calculations. Astronomical odddities, or simply generally lesser known phenomena, are easily described.
And though it deals heavily with the deepest reaches of outer space, this story is ultimately human. It's about the moral issues of discoverers and the thieves who underhandedly steal their discoveries; about the petty jealousies of chatroom mavens who believe they can stop the naming of a new stellar body, or judge when information on that body should have been delievered; about the international gathering of astronomers who deal in the politics of topics like the definition of "planet"; and it's about the author himself, his personal growth during the time period in which the latest chapter of the Pluto story unfurled, from single life to fatherhood.
The book is eye-opening, too, for the connections between astronomy and ancient cultures. Those men and women dedicating themselves to finding new planets have to know not only the stars, but some mythology, as well. And you'll be amused to find out what Xena the Warrior Princess, of television mythology, has to do with Pluto.
In the end, it's just one side of the story. There are plenty out there who stand against Mike Brown, and will tell you other things. But it's one heck of a good read. (It was also my first read on an e-reader).