I post a lot about Pluto and the definition of “planet”, given that I keep saying that I don’t have a stake in it and don’t particularly care how Pluto is classified. It’s fun to write about, and of course it’s pedagogically interesting — the debate is a snapshot of how science works in practice, with personality clashes, emotional outbursts, and the occasional Scientist Behaving Badly. What’s not to like?
With all of that, of course I had to obtain and read Mike Brown‘s book How I Killed Pluto and Why It Had it Coming. (Yes, I know this book came out last year. If you want me to review books faster, hire me and I’ll be able to afford to buy them more often.) Brown of course is the astronomer who led or participated in the discovery of Eris, Quaoar, Haumea, and various other distant icy objects, helping shape our view of the outer Solar System. Eris is more massive than Pluto, but in a sense it’s just the most prominent example of why Pluto isn’t unique, and this is what brought the question of what should be called “planet” to the forefront of public attention.
How I Killed Pluto is about half science, half memoir. Much of the book is a love letter to Brown’s wife Diane and daughter Lilah; their shared lives intertwine with discovery and public brouhaha to make a very personal and occasionally hilarious narrative. Those of us with actual research experience will nod or laugh in recognition of the ups and downs he goes through (though few of us can list the same level of accomplishment — we have to satisfy ourselves with much less). We’ve all been in the doldrums where things aren’t going as planned, where anything seems better than the work in front of us; Brown describes this as well as the thrill of discovery — and the nagging doubts that accompany success. In other words, the book describes what it’s like to be a real scientist: a human being who does science, sometimes messes up (but fixes things!), gets distracted, gets lost in details, but gets perspective back in time.
Of course Brown discusses the Pluto “issue”, and states the issue as plainly as I’ve heard it stated. (In fact, I’ve pointed out that my students come to a similar conclusion!) If you look at the types of objects in the Solar System without a preconceived notion of what a “planet” is, you would likely not lump Jupiter and Earth and Pluto together in the same category; you would likely give them three different names. The reasons the International Astronomical Union gave for declassifying Pluto as a planet (and creating the “dwarf planet” category) are kind of lousy, yet reasonable people can agree with the end result if they can get beyond the “but I learned this in school” mentality. In fact, I recommend this book if you are of the “Pluto must remain a planet!!!” mindset; I think, even if you still want to keep the tiny iceball a planet, you’ll at least have a better idea of why its planetary status is questionable.
All of this is written with humility and a great sense of humor. (Brown’s Twitter handle is @plutokiller, if you need further convincing.) He cares very deeply for the science he does and for the people in his life; all this love comes through in the prose. I can think of no higher recommendation than that.