A Letter from Author Mike Brown
My daughter Lilah, now five years old, is mad at me for killing Pluto. When I began a project 13 years ago to chart the slowly-moving objects of the distant outer solar system, my goal was never to pull Pluto off of its cherished planetary pedestal. I wanted to be a planet discoverer, like William Herschel or Clyde Tombaugh before me. I had a strong feeling that somewhere out there something bigger than Pluto was lurking, and I knew that whoever found it would get to claim the mantle as the only living planet discoverer.
I was right. Something bigger than Pluto was
out there (or at least something more massive than Pluto; sizes are a little harder to pin down precisely) and one January morning in 2005, my small team of astronomers and I found it. We announced the discovery of the 10th planet to an unsuspecting world late on the afternoon of Lilah’s 22nd day of life. A little after her first birthday, though, the doors to the planetary club were locked and Pluto and my own discovery were kicked out on the curb. The solar system was down to only eight planets.
It was hard not to mourn the loss of my now ex-planet, except for the fact that I had to admit that kicking it out was the most scientifically sensible thing to happen to planetary classification since asteroids were also kicked out almost 200 years ago. The solar system is a beautiful and profound place, and it is made richer
with the realization that the eight planets are the foundation throughout which countless smaller bodies continuously swirl.
When Pluto was first demoted, people said to me, “What about the children? How could you do this to them?” But, in fact, children live lives that are always changing. It’s the adults who have had the hardest time reconciling the new understanding of the solar system with what they remember from when they themselves were children. So, it made sense that I used to joke about what would happen the moment when Lilah first learned about the solar system. She would come home, and I would say, “Tell me all about the eight planets,” and when I would try to tell her about the olden times when we used to think there were nine—or even ten!—planets, she would slowly shake her head and exclaim, “Daddy, adults are so stupid
But I was wrong.
Lilah knows all about Pluto. She has a stuffed dog, a planet lunch box, a solar system place mat at the dinner table. She feels as warmly towards the ice ball as someone ten times her age, and, like many of those older people, she is mad at the person who killed it. Lilah, though, has a solution. She recently told me, “Daddy, I know that you had to kill Pluto, but will you promise me one thing?”
“Of course,” I said.
“You have to go find another planet, and when you do, you have to name it Pluto for me, OK?”
So my search of the skies continues.
Though several reviewers admitted a grudge against Brown for picking off plucky underdog Pluto, they found his memoir a charming account of a scientist’s life and work. Given Brown’s popularity as an instructor and lecturer at Caltech, it is perhaps unsurprising that his book is accessible and enlightening. Critics were less certain about Brown’s decision to include so much of his personal life in the book. None actually said that Brown’s interludes about becoming a husband and father detracted from his story, but a few asked what they really added. Others, though, felt that this personal perspective perfectly rounded out Brown’s account of how he and his discoveries reshaped the solar system.