How I Killed Pluto and Why It Had It Coming - Mike Brown [26]
The difference between the digital camera and the old photographic plates was extreme. With the plates, you would walk upstairs, load the photographic plate, open the enormous shutter on the camera, and expose the film to the sky for about twenty minutes. It would take about ten minutes to unload the exposed plate and load in a new one and start all over again. In contrast, with the digital camera, you never had to walk up the stairs—indeed, you needn’t even be awake! The computer opened the shutter, exposing the digital camera for about sixty seconds, and sixty seconds later you could be looking somewhere else in the sky. It took two minutes for the computer to do what it had taken forty minutes for Jean or Kevin to do earlier.
The digital camera was small, though, compared to the photographic plates, and it covered only about one-twelfth as much of the sky (an area equivalent to about three full moons)—but since it was twenty times as fast, we were still ahead. Even better, in the 60 seconds that the digital camera was exposed to the sky it was able to see stars and moons and planets that were two or three times fainter than the faintest things we had seen on the photographic plates. I had been worried for the past several years that the things for which we were looking lurked just beyond the limits of what we could see. I had stared at many of those photographic plates that Kevin and Jean had taken, and had wondered what we were just barely missing.
But now we were in business. We could run almost every clear night of the year without worrying about overworking anyone other than the computer. We could see fainter things. We could cover more sky. In the first four months, we planned to redo the whole region of the sky that had taken us three years to complete earlier. And then we were going to keep going. Surely, all of this would lead us to the planet that was still out there waiting to be found. I was certain we would find it quickly.
I was so certain that we were going to be finding things immediately that I decided I needed help. I recruited Chad Trujillo, who was just finishing his doctoral thesis—on, conveniently, finding objects in the Kuiper belt—at the University of Hawaii. I wasn’t sure I was going to be able to convince him to come to Pasadena. He was so relaxed from his years in Hawaii that he seemed like someone more likely to live in a tree house than in a city, but having lived in the little cabin up in the woods in my earlier years in Pasadena, I knew where to find the most tree-houselike areas around. That, and the prospect of perhaps finding a planet or two, convinced him, and he moved to Pasadena and immediately set to work.
He knew what he was doing so well and was already so good at it that I essentially handed him the keys to the telescope and stepped out of his way. In a few short months, we’d finished looking at the area of the sky we had previously covered with photographic plates, and, to my great relief, there truly was nothing there to have been seen. Soon we were on to fresh sky. And somewhere in that fresh sky we made our first catch.
I’d love to write more about this very first discovery, about how Chad took pictures of the sky one night and then, while looking through them the next day, spotted a brand-new point of light slowly crawling across the images. I’d love to describe Chad’s excitement as he stepped across the