How I Killed Pluto and Why It Had It Coming - Mike Brown [22]
I knew that the computer would be overzealous in identifying potential planets; in fact, I had written the program to make sure that the computer was overzealous. I had decided early on that I would make the computer find everything even remotely possible, and I would look at each thing the computer picked out by eye to double-check it. But 8,761 objects to check by eye was going to take a long time.
I slowly began to go through the list. I would press a button on my computer, and on my screen three pictures would appear of the three nights of the same small region of the sky, with little arrows showing where the potential planet lay. I saw an amazing number of small glitches that had fooled the computer. Scratches on the photographic plates, of which there were many, would cause a star to disappear one night and so appear as if it were new the next. Anyone looking at the pictures could see that it was just a scratch, but to the computer it appeared as dark sky. Sometimes the light from a particularly bright star would get reflected around in the telescope perhaps dozens of times and give tiny apparent glints all across the sky. By eye, you would notice all of the glints and you’d see the proximity of the bright star, and you would quickly say, “Ah, that’s just a bright star making glints,” but to the computer it was a star never seen before.
The examination took months. On the computer screen, I had a “no,” a “maybe,” and a “YES!” button that I chose from after examining each of the pictures. Had it been a mechanical button instead of a virtual one on the computer screen, I would have worn the “no” button through. The “maybe” button got a little bit of action, too. Sometimes I would look at three pictures and find no obvious problems with what the computer had done, but I still wasn’t entirely convinced that what the computer had picked out was really there at all. The photographic emulsion was sometimes a little uneven, and the computer might have picked out a slightly brighter spot that really was just the sky. A tiny speck might appear that was possibly a faint star, but I was not quite convinced. In all of those not-entirely-sure cases, I would simply press “maybe.”
“YES!” was reserved for the no-questions-no-problems-definitely-really-there-moving-through-the-sky cases. Every day I would come in thinking that perhaps today was the day that I would finally push the “YES!” button. Every day I would spend hours staring at the computer screen, pushing “no,” and occasionally, very occasionally, “maybe.” But the “YES!” button remained untested. After going through the entire set of potential planets that the computer had picked out, I never once used the “YES!” Final score: “no,” 8,734; “maybe,” 27; “YES!” 0.
It was hard not to feel distressed. What if there really were no other planets out there? What if three years of photographing and computing and blinking came down to nothing at all? What if the big project designed to make my splash as a young professor at Caltech disappeared without a ripple? I had been telling everyone for three years now that I was looking for planets, that I was going to find planets. What if there were no planets?
I still had hope, though, in the twenty-seven maybes. I spent much of the fall of 2001 at Palomar Observatory trying to track them down. For a few dark nights every month, I would drive to the mountaintop, arriving early in the day to plan for the night and prepare the telescope, eating dinner before the sun was close to setting, packing up a bag full of truly awful snacks designed to keep me awake throughout the night, and then heading for the control room of the 60-inch telescope.
This telescope had a modern digital camera, which meant that it was quite sensitive but that it covered a tiny area