Read How I Killed Pluto and Why It Had It Coming Online
Authors: Mike Brown
Not wanting to wait forty years, and it being 1998 instead of 1930, I put the computers to work instead. First, we needed to scan the photographic plates to get them into digital form, and then the computer could do the rest. The scanning was quickly done on a big machine that already existed. Getting the computer to do the rest, though, took longer. There is no software package that looks for planets. I would have to write it myself. Though I knew nothing about emulsion and developer and fixer, this I could do. This I was good at. I had been writing little computer programs to analyze and predict and follow the stars and moons and planets in the night sky since high school. This would be the first program that actually mattered.
I spent most of that year slouched in front of a computer screen in my office, testing, scowling, starting over, typing furiously, and pondering. For someone looking for planets, I spent an awful lot of my time looking at computer code and numeric outputs instead. My nights were spent not outside staring at the sky but inside staring at numbers and computer programs and
doing every test conceivable. I needed to make sure the software wasn’t going to make any mistakes. I wanted to make sure that I didn’t do anything stupid that made me miss planets that were right in front of me.
I made the computer begin by looking at a triplet of scanned photographic plates. It examined each of the little blips of light on each of the three images taken over the three nights. All of the stars in the sky, all of the galaxies, all of the nebulae, had the same coordinates on each of the three photographic plates, so the computer quickly identified them as not moving and tossed them aside. Sometimes, though, something appeared at a spot in one image where the other two images showed only blank sky. The computer took note. It could be many things. Sometimes stars in the sky get brighter and suddenly show up where they weren’t seen before. Sometimes satellites in orbit around the earth give a sudden glint that looks like a star. Sometimes dust blowing around at night sifts through the open shutter of the telescope and settles down on the photographic plate, disturbing the precarious emulsion and making something that looks vaguely like a star. But sometimes something appears where it has never appeared before because it is slowly wandering across the sky and that single picture happened to catch it momentarily in one spot. In that case, an image the next night would find it again, only a little displaced from the previous night. I used the third picture as a final check. When the computer found a third object that looked as though it could be connected to the first two, it put that object on a list of potential new wanderers and moved on to the next spot in the sky. All of this takes, of course, about a millisecond. To process our two years’ worth of images took under two hours.
So after Kevin and Jean had spent all of those nights loading and developing plates, and I had spent a year programming the
computer, and the computer had spent two hours processing all of the final data, I finally had a list of all of the potential new planets to look at. I had been sustained throughout this time by the thought of this moment. I was going to find a planet, and the solar system would never again be the same. When I first opened up the list on the computer screen and started scrolling down, I must have gasped. The list was 8,761 candidates long.
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 “Y
ES
!” 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.”
“Y
ES
!” 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 “Y
ES
!” button. Every day I would spend hours staring at the computer screen, pushing “no,” and occasionally, very occasionally, “maybe.” But the “Y
ES
!” button remained untested. After going through the entire set of potential planets that the computer had picked out, I never once used the “Y
ES
!” Final score: “no,” 8,734; “maybe,” 27; “Y
ES
!” 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 of sky. The nights were carefully choreographed so that I could spend the most time looking at the expected locations of the twenty-seven maybes. Because a full year had passed, they had moved quite a ways, and it was impossible to know precisely where they might be, so I would spend hours scouring large parts of the sky, taking a picture, and coming back to the same spot an hour later and taking another picture. I didn’t even bother writing a computer program for these; I would just look at the blinking images on my computer screen the second that they came down from the computer. All night, every night there, I would take a picture, move the telescope over, immediately start another picture, stare at the last picture while taking the current picture, and continue on until dawn. Then I would slowly and wearily walk the winding road the half mile back to the Monastery, often startling foxes or bobcats out for a dawn hunt. Around noon, I would wake up, have breakfast, and begin the day again.
During those first few months tracking down maybes, I felt excited when the sun went down.
Tonight is the night! I would think.
As the fall progressed, though, I was slowly becoming dejected.
I spent so much of my time at Palomar Observatory that fall that I didn’t have to think twice when I got a request to give a talk at the observatory to a group associated with Caltech. I was going to be there the night before anyway, so I figured I might as well stay one more night to give the talk. On my calendar I just wrote “talk to some group.” The group was to arrive by bus in
the late afternoon, take a tour of the massive Hale Telescope, and eat dinner and hear my talk on the floor of the dome with the telescope perched overhead. It sounded fun. I like giving talks to groups like this.
The afternoon the group was to arrive, I waited on the dark ground floor of the observatory until I heard a knock on the door. As I opened it, I was blinded by the afternoon sun. When my eyes adjusted again, I finally saw the organizer of the tour walk in.
“Hi, I’m Diane Binney,” she said.
She was well dressed, poised, glamorous, outgoing, radiant. She was everything that you don’t stereotypically expect to find in someone from Caltech (including, in particular, me). I quickly introduced myself, and I thought: Who
is
this person?
Diane Binney was the well-loved director of a group whose members attended tours and special talks and traveled to exotic locations, all associated with Caltech and its research. Diane had arranged this trip to Palomar Observatory and had invited me to speak, and, as I learned much later, everyone except for me on the Caltech campus seemed to know precisely who she was and had known for years. I had perhaps been staring into my computer screen too much to have ever looked up and noticed.
I admit that I did not give the people on the tour the full attention that they deserved. I admit to spending more time telling Diane about the telescope and the dome and astronomy than I did everyone else. But I must have given an all-right tour—at least to her—because at some point while walking on a catwalk high above the ground on the outside of the observatory, she said, “Hey, do you ever use the telescopes in Hawaii?”
I do.
“Would you be interested in coming next spring on a travel program where we take people to the volcanoes and then up to
the telescopes? Would you be able to talk about the telescopes and give tours?”
Not checking my calendar, I simply said, “Absolutely.”
Dinner soon began. I spoke for an hour and showed pictures of the sky, pictures of telescopes, and graphs of what was to be found out at the edge of the solar system. But mostly I talked about planets. I told the group that there
had
to be planets out there and that I was going to find them. Even as I said it, though, all I could think of was that I was halfway through my “maybe” list, and still I had found nothing. I could do the song and the dance and put on the excited face, but it was becoming possible that all of my searching would come to nothing.
When the talk was over, the group got on their bus and left. I walked over to the little cottage where Kevin Rykoski lived. I had talked to Kevin and Jean Mueller on the phone every night discussing where to point the telescope, but now I finally had a chance to go sit on Kevin’s sofa and drink a beer. He had been at my talk earlier and had helped with the tour.
Over time, my conversations with Kevin and Jean every night while taking the photographic plates had progressed from simple efficient talk about the sky and the weather to a more general extended chat. Jean would talk about her plans for a dream house on the river, while Kevin told stories about his teenage daughter or described how he would drive directly to the beach on the last morning before bright time started and sleep all day long. Kevin and Jean had also had inadvertent front-row seats to the demise of my long-term relationship from my days in Berkeley and my subsequent retreat from the cabin in the woods that my girlfriend and I had shared, to the death of my father, to the start and end of a new relationship or two; so, as I sat on Kevin’s sofa for the first time, our conversation naturally steered to the personal.
All Kevin wanted to talk about was Diane Binney and why she kept talking to me. I told Kevin about the Hawaii trip and that we were talking logistics. He thought that sounded like an exciting first date. I insisted that it sounded like work, because that was all it was.
Kevin wouldn’t let up. “Yeah, but she was paying you a lot of attention.”
“She runs trips for people; it’s her job to be nice. I’m sure that all of the guys at Caltech that she has to work with get the wrong impression and make idiots of themselves. I’m not going to do anything stupid.”
Six months later, I was in Hawaii with Diane and twenty or thirty people in her group. The group spent an enjoyable week on the lava, at the telescopes, at the beach, learning about geology and listening to me lecture about astronomy. The last night, when she was done with the trip and could finally relax, the two of us found ourselves down on the beach alone sometime after midnight. I pointed out the Southern Cross, just barely visible at the right time of year from Hawaii, and I showed her the paths of the planets and how she could pick out Saturn just setting into the ocean. I told her what it was really like to use the telescopes, and she talked of her nieces back in California. Saturn sank into the Pacific, and we finally walked back to our rooms. I was quite proud of myself for not having done anything stupid.
When we got back to Caltech the following week, I found myself accidentally walking past Diane’s office a few times a day and accidentally running into her and stopping to talk. Every time I did, she was very nice, and I had to remind myself that, truly, it was her job to be nice and to appear happy to see me and that being stupid was the worst thing to do. On accidentally running into her in the early afternoon one pleasant spring workday, I asked if she needed a cup of coffee. She did. We
walked down the street, drank coffee, and talked for three hours. Certainly, it was part of her job to be nice to me and cultivate me as a good resource. But it occurred to me that, even accounting for all of that, there was no reason for her to spend three hours in the middle of an afternoon with me when we both had many other things to do. It suddenly occurred to me that, in fact, I had been stupid all along.