How I Killed Pluto and Why It Had It Coming (12 page)

“Sure, I know Mike; he’s the guy who is engaged to Diane Binney. Hey Mike, I want to introduce you to my friend—hey, do you know Mike Brown? He’s the guy who is engaged to Diane Binney.”

“Sure, I know Mike Brown—he’s the guy who discovered that thing out past Pluto. Let me introduce you to a friend who is really interested in planets.…”

Even today I spend much of my time exploring the outer edges of the solar system, looking for little worlds that have never before been seen, wondering what else is out there on the outskirts of our solar system. Someday I will have looked everywhere that the telescopes I have are capable of seeing, and then I guess I will have to declare that my days of exploring are finished.

It will be nice to finally stop fretting every night when I see a few clouds in the sky as the sun goes down, or when the moon is nearing full and I know that the section of sky we wanted to cover this month is not quite done. It might be nice to wake up in the morning and see red-tinged cumulus clouds beautifully strewn across the L.A. basin and not have to wonder what we missed last night. And even though the computer does most of the hard work of looking at all of the data and finding the things that move, something always goes a bit wrong and I am always fixing a little bit of computer code or making slight improvements. The computer even sends me text messages on my cell
phone when something goes really wrong. More often than not, it seems, trouble occurs on Saturday mornings while I am sitting drinking my coffee.

Still, the fact that on any morning I might walk into my office and see something moving across the sky that no one has ever seen before, something bigger than anything found in perhaps a hundred years, adds an element of excitement to my life. I will be sad to be done, and what will I do after that?

I did almost quit once, a little more than a year after the announcement of Quaoar. I thought, at the time, that we had reached the end of the solar system.

Chad had moved back to Hawaii by then, eventually to marry, buy a house on the rainy, steamy, jungly northeast side of the Big Island, and work on telescopes. He and I (though, really, mostly he) had spent two long years staring at the sky night after night, and by the end of the two years we had covered 12 percent of the whole sky. While this might not seem like a huge amount, this time we really had covered a wide swath of the parts of the sky where we expected anything big to be. If we looked farther north or farther south, we would be looking away from the region where all of the planets are. The only things that we would find in the regions farther north and south would be things that went around the sun in orbits even more tilted than Pluto’s. The chances that something like that was out there seemed remote.

I don’t mind taking bets on remote chances. Perhaps you could have said that our chances of finding something as big as Quaoar were remote, too, but there it was. The chances I would meet the person that I was going to marry in the basement of the 200-inch Hale Telescope were even more remote, but by now Diane and I had been married almost six months. Remote chances lead to good things, as far as I can tell.

So in the fall of 2003, just as Chad was leaving and our two-year
project to use the little telescope at Palomar to scan the skies for planets was ending, I began a new project about which I was quite excited. I was going to use the same telescope to scan the skies for planets. For the third time. This time, though, I wasn’t going to concentrate on the most probable places, I was going to concentrate on some of the least probable. The project was going to be even better than before, too, because other astronomers had become interested in using the telescope to look at vast areas of the sky for very rare quasars flickering at the edge of the universe, and they had built an even bigger camera—the biggest astronomical camera in the entire world!—to look at even bigger areas of the sky at once. This seemed, at least at first, like great news for us. We would sweep through the unsearched regions of sky faster than ever before.

Right before Chad moved back to Hawaii, he modified all of the computer programs he had written over the previous three years so that they would work with this new supercamera. He automated everything as much as possible so that the project could continue in his absence. I was a little nervous about this, because it meant that I was stepping in to be the one in charge of the night-to-night workings of the project. I had been letting Chad take all of the major responsibility for years now, and in that time, I’d had many other projects going on to worry about and spend my time on. But things looked good. It looked as though with just a little bit of babysitting from me everything would run smoothly, the skies would be ours, and I could keep my day job.

The new camera arrived about a month after Chad left, and it spent its first night taking pictures of the sky. At the end of the night, I set Chad’s computer programs to search once again for distant planets, for things that were moving in the sky. The computer worked all day long, as I carried on with all of the nonplanet-searching
projects that were supposed to be occupying my time. Finally an automated e-mail informed me that the program was done. I opened up the file to see if the program had found anything. It had! Not only had it found things moving in the sky, it had found thirty-seven thousand of them!

My heart sank.

There could not possibly be thirty-seven thousand real moving objects in pictures from that night. In fact, I now know that there was precisely one.

The computer was confused. But it was not Chad’s program that was the problem, it was the fancy new camera. To make the biggest astronomical camera in the entire world at a price that was not astronomical, the builders had had to compromise a bit on quality. One of those compromises had led to an incredible number of smeared spots, dark blemishes, light dots, black streaks, and bright blots showing up in each and every picture of the sky. The computer doesn’t do a good job of distinguishing between bright blots or light dots caused by the camera and those caused by something actually in the sky. Those thirty-seven thousand moving objects were almost all camera junk.

I had not expected the computer or the camera to be perfect. I had anticipated that every morning I would have to look through
some
of the pictures to sort out the real objects from the fake ones. I had even taken the time to write a quick computer program to make this sorting extremely efficient; I could simply sit at my computer, press a single button, and a little postage-stamp-sized bit of the pictures from the previous night would appear on my screen. Three images would blink through in succession, and by eye, I would quickly be able to see what the computer had thought was moving. The eye is really good at finding the computer’s mistakes or verifying true finds. After some practice, I could look at perhaps as many as twenty different candidate
objects in a minute. But to look at thirty-seven thousand would take me thirty hours straight for every one night’s worth of data. This was potentially a disaster.

I sent an e-mail to David Rabinowitz, an astronomer at Yale University, describing the problems. David had helped build the new camera and had joined Chad and me as the third member of our planet search team; if anyone knew any clever solutions to the problem, it would be David. He quickly responded: There was nothing that could be done to fix the camera’s problem.

The only plausible solution I could think of was to somehow make the computer program much, much smarter. But Chad was on to a new job and new responsibilities and couldn’t spend the next two years writing new computer programs the way he had for the previous camera. And even if he
was
working on this project, I couldn’t think of an obvious way to make the computer program smarter. Everything that I could think of doing to get rid of the thirty-seven thousand camera-junk objects had a chance of getting rid of the real objects, too.

There was one solution: I could quit. Shut the project down. Declare an end to the solar system. In fact, it almost seemed like a good idea. Our chances of finding new objects were remote. The effort to find them was going to be extreme, if not impossible. If ever there was a time to cut our losses, now was it.

I needed a second opinion. I walked up the road to my favorite café with Antonin Bouchez, one of my graduate students at the time and someone whose opinion I greatly trusted.

“I’m done,” I told him. “We’ve looked at enough sky; if there was anything else out there, we would have seen it by now. The new camera is low quality, and I don’t think there is really any way to move forward.”

I laid out all of my reasoning. I outlined the regions of the sky we had covered. I talked to him about the very slim probability
of finding anything else. I showed him data on the new camera.

“You’re crazy,” he said.

“No no no,” I told him. I went through the arguments again. Look at the problems with the camera! Look at how well we’ve already done with the sky!

“No, really, you’re crazy.”

We drank more coffee. I described how I believed the solar system was laid out and why it now seemed clear that there was nothing larger than Pluto out there to be seen. And thirty-seven thousand moving things to look at in one night? Impossible!

“Do you really believe there’s nothing else out there?” he asked.

“I do,” I said.

“So how are you going to feel when you pick up a newspaper one morning and read about someone discovering something right where you didn’t look?”

I was reaching for the coffee again but stopped short. “Uhhhhhh. But it’s not going to happen since we’ve reached the end of the solar system.”

“What if you’re wrong?”

What, indeed? Ten years earlier almost no one had thought that there was anything to be found beyond Pluto at all and that anyone spending all of his time looking was crazy. Even just two years earlier almost no one had thought that something as big as Quaoar would be found and that anyone spending all of his time looking was crazy. I hadn’t bothered believing what most people thought back then, so why was I bothering to believe what most people thought now?

“Do you really know there is nothing else out there?” Antonin asked again.

Well. Okay. No. I really didn’t.

“Then why exactly do you want to quit?”

Because it was going to be hard work. Because I didn’t have help anymore. Because I wasn’t certain I’d be able to pull it off alone. Because I had been working on it for a couple of weeks and had hit what felt like insurmountable roadblocks.

Looking back from a perspective of more than half a decade later, I think of this conversation as being as momentous as the moment when Diane walked through the door of the 200-inch Hale Telescope that first time that I saw her and my life irrevocably changed. A decade of floundering had ended that moment. This time the floundering had been for only a few months, but I had been floundering nonetheless. I can now even identify what the problem was, though I couldn’t have done so at the time. My biggest problem was not that the camera had specks or that the software was not up to the task. My biggest problem was that I had let myself become a normal person instead of an astronomer. I was believing what most people thought, because “most people” now included me.

When I hired Chad and set him to work, he was so good at it that I had spent most of the previous year or so enjoying my life. Most nights I even left work at an almost reasonable hour and went home and made dinner for Diane—and the nights I didn’t were usually because
she
was working late, not me. In the year before the new camera had been connected, Diane and I had married, gone on a monthlong honeymoon to South America, been on vacations, fixed up our little house. In short, we were behaving like normal people. I had never quite behaved like a normal person before.

I could do all of this because Chad was hard at work every night scanning the skies. And he periodically let me know how it was going. But, really, I didn’t know much about the details of what he was doing.

Now Chad had moved on to a new job, and I was left with a big complicated system that was suddenly mine alone. And a major component of the system had just changed, and everything needed to be fixed, and no one knew how to do it.

Antonin and I were still drinking our coffee. “Keep looking,” Antonin said. “How could there be nothing left to find?”

I had used that same argument myself. How could there be nothing left to find? How could this really be the end of the solar system?

I drank more coffee. I stared into space. How would I do it? There was no way I could get someone up to speed quickly enough to keep going. We were still scanning the skies every single night. I didn’t have the time to wait months or years for someone new to come on board to get things going. I needed someone right now.

And then I thought of someone who was actually pretty good at this sort of thing and even knew a bit about it already. Me. It would mean an end to being normal, to going home most nights and cooking dinner, but it would mean that the solar system didn’t have to end.

I finished my coffee, and Antonin and I headed back toward campus, but I took a quick detour to Diane’s office. She was between meetings. I told her about the problems and the 37,000 objects and about the solar system that I didn’t want to end and how the only solution was to start doing all the work myself. She looked at me, smiled, and said, “Go find a planet.”

In the end, the solution to what to do with 37,000 objects in one night turned out to be deceptively simple: I let it go. After a few more nights of collecting data and finding 33,000, 50,000, 20,000, and 42,000 objects, patterns began to emerge. Almost all of the camera junk turned out to be in a few places on the images. If I just threw some parts of the pictures away, ignoring
what was there, then everything else was suddenly manageable. That meant, of course, that if something real was there I had to throw it away, too. But it was a price I was willing to pay. I finally settled on throwing away about 10 percent of the sky to get rid of 99.7 percent of the camera junk. For the first night’s worth of data, I went from 37,000 potential objects to look at to about one hundred. I could handle one hundred.