How I Killed Pluto and Why It Had It Coming by Mike Brown

So, it made sense that I used to joke about what would happen the moment when Lilah first learned about the solar system. 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. 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. 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. 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 was down to only eight planets. 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. We announced the discovery of the 10th planet to an unsuspecting world late on the afternoon of Lilah’s 22nd day of life. 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. 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 wanted to be a planet discoverer, like William Herschel or Clyde Tombaugh before me. 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.

My daughter Lilah, now five years old, is mad at me for killing Pluto.

How I Killed Pluto and Why It Had It Coming by Mike Brown