How I Killed Pluto and Why It Had It Coming - Mike Brown (2010)


On the morning of the twentieth day of Lilah’s life, only a few days after dumping kitty litter into the washing machine, I received a strange e-mail. A NASA official in Washington, D.C., wanted to know about Santa, which he called K40506A, the name my computer program had automatically assigned it on the day of discovery (K for Kuiper belt, 40506 for 2004, May 6, and A for the first one found that day). A colleague across the country was interested in studying K40506A, and the NASA official wanted to know when we were going to publicly announce the discovery.

My sleepy brain tried to make the connection: How would someone at NASA know about Santa, and, stranger, how did he know to call it K40506A? Had I told someone about it in the past few weeks? I couldn’t remember mentioning it to anyone. Baffled, I did a quick search through my e-mails since Lilah’s birth. Nothing but back-and-forth baby news and pictures. But the e-mail did jar my brain enough to remember that sometime in late July (and wasn’t it now late July?) an online announcement would be made of the titles and subjects of hundreds of talks that would be given at an international planetary science conference in September. And near the middle of that list of talks were one by David and one by Chad, each talking about something that they called K40506A and which they declared to be the brightest object in the Kuiper belt. I, being on family leave, had no intention of attending any conferences anytime soon, but I was nonetheless listed as a coauthor on both of their talks.

I checked online and sure enough, the titles had been posted a day or two earlier, and people were already poring over them to see what we—and everyone else—were up to in advance of the actual meeting.

In the late afternoon, I wrote back to the NASA official and the distant colleague and said that we planned an official announcement of K40506A at the meeting in September, but that if it would be helpful for their research (and they could keep a secret), I would be happy to share the coordinates of the object earlier. I tried to be smooth and wrote:

We weren’t planning on making much of a big deal about this one. The mass is 32% that of Pluto, based on an orbital solution of its satellite. But we figure people are tired of hearing “almost as big as Pluto.” We’re waiting now for “bigger than Pluto.”

Waiting, indeed. We were still months away from the planned announcement of Xena and Easterbunny, but the wait would be much shorter than I imagined.

I spent the next forty-five minutes cooking dinner, washing dishes, and putting real laundry detergent in the washing machine. Lilah woke up from her nap. Diane fed her. Lilah went back to sleep. I fed Diane. Diane went back to sleep. I fed myself. I was about to go back to sleep but instead checked my e-mail again.

An even stranger e-mail this time, from a colleague with whom we had already shared information about Santa so that he could help us with some of our ongoing studies. All he wrote was:

Mike, is this one of yours?

What then followed was a list of dates and positions in the sky of the location of an object discovered a day or two earlier by—by whom?—a name I didn’t recognize, at a telescope I had never heard of.

My brain clicked in a little as I scanned the sky coordinates on the list. I’m not the type of guy to memorize coordinates of everything in the sky, but I knew that Santa was high in the midnight sky in about the April time frame. So were the coordinates on the list. I knew how bright Santa was; the brightness of the object on the list agreed closely.

My sluggish brain was now trying to accelerate to full speed for the first time in nineteen days. I did some quick calculations to get the precise coordinates of Santa on the days on the list, and I compared. Perfect fit. Santa had been found.

I remember this moment as a sharp pain in my stomach. We had been scooped. After discovering Santa six months earlier, and working hard to do a thorough job and write a scientific paper on the discovery (and failing, by one day, because of Lilah being born just a bit earlier than I had expected), someone had come out of nowhere and kicked us in the gut.

Who were these people, and what right did they have to take my objects? My objects! Santa had been my baby for six months already. I looked up the culprits. I had never heard of them. They were at a small Spanish university, and they had never discovered anything previously. How could this have happened?

Chad sent an e-mail; someone had told him, too. He wrote:

Someone found Santa and beat us to the discovery!

There must be a way to make this all go away, I remember thinking. Maybe we could explain that we knew about it first. Or that our talk title was our announcement, our proof that we had been there first. Maybe there was still some way to salvage our discovery. There had to be a way. I was exhausted, but I knew that, with some sleep, I could find a way.

I heard Lilah cry. Diane was still trying to take a little post-dinner nap, so I let her sleep and went in to check on Lilah. I put on some music and danced with her for a while in her room. Just a few days earlier she had started making real smiles. She made one then. I sat down in the rocking chair with her until we both fell asleep. A few minutes later I opened up my eyes, put her down in her crib, and went back to my chair.

I had figured out a way to make it all right.

I sent e-mails to Chad and David telling them the details. I sent an e-mail to the NASA official with whom I had promised to confidentially share the position of Santa, saying that there was no longer any need for secrecy. And I started answering inquiries from the press who had seen the announcement and were already starting to take notice. They wanted comments from the guy who usually found these large objects out in the Kuiper belt, and they wanted to know how someone had beaten me to it.

Diane woke up and came in the room, and I told her what had happened. She protested that Santa had been my discovery, and I explained to her that no one owns the sky. If someone points a telescope at something, sees it, and announces it for the first time, it is that person’s discovery, even if I knew about it earlier. In science, the first to announce takes the prize. The Spanish astronomers had announced Santa first, therefore they were the discoverers. Not only was there no argument that we could use to say otherwise, I didn’t want to argue otherwise. I think the system is a pretty good one, even when it means I get scooped.

Perhaps this was even a good thing, I explained to Diane. In a few months we would be announcing Xena and Easterbunny—both even bigger than Santa—and having an earlier announcement of a large object from a different group in a different country on a different continent added a bit to the excitement of it all. I could not have come up with a better plan myself.

Diane, without the benefit of the adrenaline that had been pumping through my system for the previous hour, stared at me as if I were a lunatic. But as lunatics go, I was not too crazy. With the question of who discovered Santa now settled, we might as well make something good out of it.

Diane went back to sleep, while I went back to my e-mail.

The astronomical-media grapevine had picked up on the fact that K40506A—the object that Chad and David had included in the titles of their talks at the conference in September—was the same as the new object just announced (which now had yet another name: 2003 EL61, based on the fact that the astronomers who had discovered it found it by looking through old images from 2003, much as I had been looking through old images myself when I found it). A headline from the BBC blared: “Conflicting Claims in Planetary Discovery.” The article breathlessly exclaimed how astronomers were already passionately arguing about whose claim was legitimate and how the dispute was bound to reach the highest levels of the International Astronomical Union. And that the object could well be twice the size of Pluto.

Twice the size of Pluto? We knew, of course, that 2003 EL61 or Santa or K40506A or, later, Haumea was only about a third the mass of Pluto. We had followed the orbit of Rudolph, the tiny moon going around Santa, and had accurately determined the mass in the process. But the new discoverers didn’t know anything about the moon. They had discovered Santa/2003 EL61 only a few days earlier and hadn’t taken the time to do anything but make the announcement. Nobody knew about the little moon, because I had never quite finished the paper announcing its discovery.

I suddenly acquired a new worry. If the press started gushing about something potentially bigger than Pluto that turned out to be only a third the size of Pluto, what would happen in a few months when we announced the existence of something that really was bigger than Pluto? Would people simply say, “Oh yeah, we heard about that one already”?

With the perspective of the years that followed, and with the help of a reasonable amount of sleep, it is now clear to me that my worry was misplaced. Things that are real, that are important, will go into textbooks, into documentaries; they will become part of our culture. Everything else will fade. Still, at the time, I thought it very important to do two things. First, I wanted to make sure that no one could possibly claim that I was attempting to steal any credit for the Spanish team’s discovery, and second, I needed to make sure that everyone knew as quickly as possible that 2003 EL61/Santa was only about a third the size of Pluto.

First, to quickly answer all of the e-mail questions I was getting from reporters, I made a website describing 2003 EL61 and what we knew about it. I put a picture of Santa and its moon Rudolph on the site, showed the orbit, and explained how we knew that Santa was only a third the mass of Pluto. I described how we had found it back during the previous December and were preparing a paper describing the discovery. And then I wrote extensively about why I thought that the accepted scientific practice of assigning discovery rights to the first person to announce was the right thing to do.

Why was it the right thing to do? It is the only way I can think of to strike the right balance between the desire of the broad community to have all information be public immediately and the desire of the individual to keep a discovery secret for years while slowly studying all of the implications and making all of the important findings before anyone else gets a crack at it. Both of these are natural desires. Neither of these is a particularly good idea. Instant disclosure leads to unvetted science being thrust into the community (such as the claim that 2003 EL61 was twice the size of Pluto), and it leads to a lowering of the incentives to make the discoveries in the first place. On the other hand, keeping discoveries secret prevents the broader scientific community from learning even more about the discoveries.

It took science a while to settle on the present system. In 1610, while watching Venus with his new telescope, Galileo noticed that it went through phases identical to those of the moon. He knew that his discovery was big, and he wanted to make sure everyone knew he had found it first, but he also knew that the discovery would be even better if he could wait just a few more months for Venus to come around to the other side of the sun and show the opposite phases. I understand how he must have felt, waiting for his planet to emerge from behind the sun; Xena still had another month to go before I could finally see it with the Keck telescope. To prove that he had already discovered the phases of Venus, Galileo wrote to Kepler, “Haec immatura a me iam frustra leguntur oy,” which translates as something like “This was already tried by me in vain too early.” In case anyone else later claimed to have been the first to discover the phases of Venus, Galileo would be able to point out that his note to Kepler was really an anagram for “Cynthiae figuras aemulatur mater amorum,” or “The mother of love imitates the shape of Cynthia”: The mother of love—Venus—imitates the shape of Cynthia, the moon. The fact that Venus goes through phases just like the moon instantly proves that Venus goes around the sun, not the earth. Two millennia of understanding of the universe around us had to be thrown out the door at that moment.

These days anagrams don’t count. You have not officially discovered something until the moment of a scientific announcement.

I explained all of this on the website I put up overnight. Even so, I was tempted to add an anagram of my own: “The neat white elephant enthralls,” which rearranges as: “The tenth planet is near the whale,” which obviously refers to the fact that Xena is in the constellation Cetus, the whale. Unlike Galileo, though, I resisted. I was going to take my chances with Xena and Easterbunny.

Sometime in the late evening, I noticed an e-mail from Brian Marsden—gatekeeper of the solar system—with whom I had interacted on all of the other discoveries. He found the Spanish discovery suspicious, coming the same day as the name K40506A had appeared in public. He wanted to know if there was any way that the Spanish could possibly have been able to figure out where Santa was simply from knowing the name K40506A.

No chance, I said. It would be as if I’d decided to nickname some city somewhere in the world Happytown, and simply hearing the nickname, someone had picked up a globe and pointed to the right spot. No chance whatsoever, I told Brian.

Around midnight I started working on the second part of my plan. I wanted to make sure that no one thought I was going to stake a claim. I wrote directly to the discoverer, an astronomer named José-Luis Ortiz.

Dear Dr. Ortiz—

Congratulations on your discovery! We found the object, too, about six months ago and have been studying it in detail for the past few months. It has a few interesting properties that you might find interesting. Most interestingly, it has a satellite, and the orbital solution gives a system mass of about 28% of that of the Pluto-Charon system. It’s still probably the biggest KBO around but it has a sufficiently high albedo that it is not quite as big or massive as Pluto. I’ve got a paper describing the satellite that, ironically, I was planning to submit tomorrow. I will forward the paper to you as I submit it.

I am sure that I will get inquiries about your new object from different people; is there [or is there going to be] a website describing your survey or your discovery that I can point people to?

Again, congratulations on a very nice discovery!


A critical analysis of my e-mail suggests several things. First, I repeat the word interesting a lot when I am tired. Second, I was amazingly generous for someone who hours earlier had been trying to figure out how to turn back time and claim the discovery. If Ortiz had heard the stories that we were going to put up a fight, he must have been quite relieved to get this friendly e-mail congratulating him on his discovery. Third, I parsed my words very carefully. We “found” the object, but Ortiz had “discovered” it, and I repeatedly called it “your” object. But I was not 100 percent straightforward. The claim that we were planning to submit the paper the following day was now true, but it hadn’t been true until we’d learned of this discovery. Overall, when I look back on this e-mail years after the fact, I am proud of myself for having written it.

Lilah was awake for a late-night feed, and it was my turn. She drank quickly and went back to sleep, not aware that anything in particular was going on.

I had one more task that night before going to sleep. I needed to finish the paper about Santa. I dug out my notes from twenty days earlier and tried to remember what else I had left to do. Very little, it turned out. In only a few more hours, I had tidied up the manuscript, finished one more calculation, uploaded everything to the website of the scientific journal, and pressed “submit.” The paper that was supposed to accompany the announcement of the existence of Santa was on its way, though it was now a paper describing an object called 2003 EL61 that had been discovered by someone else. I linked the paper to my own website so it could be found by all and crawled to bed as Diane was getting up to feed Lilah.

I didn’t sleep. Brian Marsden’s question about a link between “K40506A” appearing publicly and the Spanish discovery kept circling in my brain. Still, I couldn’t imagine how the name K40506A could be used to discover Santa. Finally, I got up, went back to my computer, and googled “K40506A.” First up were the stories now appearing overnight about the discovery. Second were the titles of Chad’s and David’s talks. Third was something strange: a list of objects that had been observed by a telescope in Chile one particular night in May, including an object called K40506A. And it told where the object was.

What was this?

The address of the webpage was long. I went up successive levels of the tree and finally realized that the list was a record from a telescope in Chile that David had been using to watch Santa; the list was not even from the telescope itself, but rather from an astronomer at the University of Ohio who had built and kept track of the camera that the telescope used. And one of the seemingly innocuous things that he’d kept track of was what the camera he built was looking at and when.

I looked further and realized that if I fiddled with the Web address I could change the table to display different nights. The object K40506A appeared again, but now with a new position. A slight panic rose in my stomach. I kept fiddling with the Web address and kept getting the object’s coordinate on different nights. K40506A kept moving. Knowing where the telescope was pointing on successive nights as it tracked K40506A was as good as knowing where K40506A was on successive nights. And with successive nights of knowing where it was, it was only a small leap to knowing everything.

I didn’t think anyone would have gone to such lengths to steal the positions of Santa, but I suddenly had a new worry. On one of those nights when David’s Chilean telescope had watched K40506A, it had also watched K50331A and K31021C. I recognized those codes, too. They were Easterbunny and Xena. This was bad. Because the name K40506A was publicly involved in an astronomical controversy, people would certainly google the name, just as I had, and they would see a May position of K40506A. Some would take it a step further and fiddle with the Web address as I had and find even more positions of K40506A. Some would even notice that other similarly named objects—K50331A and K31021C—occasionally appeared on the lists and wonder what they were. Some would track them down. And some would be aware enough about what it all meant to calculate positions in the sky. They would suddenly know exactly what and where Xena and Easterbunny were.

In the middle of the night, I sent an e-mail to Chad and David warning them about all of this and asking if they knew how to get the information off the website in Ohio. I then wrote to Brian Marsden and told him the news, too. You could use the name K40506A and a little Google sleuthing to figure out where it was. I then explained to Brian that while I was not paranoid enough to think that Ortiz had done this to find Santa—it was inconceivable that any astronomer would actually be that underhanded—I was definitely paranoid enough to think that now that Santa was out of the bag, someone would eventually find our two other objects the same way. I then told him about Xena and Easterbunny. I told him that our goal was still to wait a few months until we had scientific papers prepared on these discoveries before announcing them.

Finally I went to sleep. I slept through two successive Lilah feedings for the first time in twenty days.

When I woke up, I told Diane everything that had happened that night. I had coffee. I bounced Lilah around the house a little bit. Then I checked my e-mail again.

The press was fascinated, both by the larger-than-Pluto part of the story and by the astronomer-fisticuffs part of the story, even though neither was true. I kept pointing people to the webpage.

Ortiz wrote back, a little overwhelmed, it seemed. He pointed me to a bare-bones website he had thrown together to describe the discovery. I added a link to his webpage from mine so people could read about the initial discovery.

Brian Marsden wrote back suggesting that perhaps I should be more suspicious. Did I not find the circumstances surrounding Ortiz’s discovery and announcement of 2003 EL61 odd?

David wrote back and said there was nothing we could do about the webpage in Ohio.

At 9:18 a.m. I got a new e-mail from Brian. It contained a list of all of the telescope positions of Easterbunny and Xena. Someone had already found all of the positions on the website in Ohio and had sent them in to the place where you announce discoveries. At the same time that the coordinates were sent to Brian, they were also sent to the Internet chat group that had been angry with me about my naming of Sedna and Quaoar. All of the information was now public, and there was no possible way to contain it. We were going to have to make the announcement right then.

I wrote to Brian with the official data and told him to proceed with the announcement. I wrote to Chad and David and told them what had happened and that we were instantly going live. And I sent one more e-mail to Ortiz:


Along with 2003 EL61, which you discovered this week, we have also been tracking two larger Kuiper belt objects. After the 2003 EL61 announcement someone tapped into an online database to see where we had been pointing our telescopes and, in doing so, reconstructed the positions of these two other Kuiper belt objects. They have now made these positions public. Because of all of this, we have had to announce these discoveries this morning.

I am very sorry that this announcement has to come the day after the announcement of your own discovery and that this will likely overshadow your very nice work. I will continue to try to make sure that you get the credit you deserve for the 2003 EL61 discovery.


Next, I needed to quickly make public webpages about Xena and Easterbunny, which would soon be getting new names. I would probably need to work on a press release. I kissed Diane and a sleepy Lilah goodbye and drove down to Caltech for the first time in twenty days.

At work, I called the Caltech press office and told the person who writes press releases, “We’ve discovered something bigger than Pluto and need to have a press release about it go out today.”

“Bigger than Pluto!” he exclaimed. “Wow! So it’s the tenth planet?”

I hadn’t figured that part out yet. I had strong opinions about planets. I didn’t believe that Pluto should be classified as a planet. The word planet should be reserved for the small number of truly important things in the solar system. Xena, though bigger than Pluto, did not rise to the level of a truly important object in the overall context of the solar system.

But but but but still.

“I don’t want the press release to say it’s a planet. Just say it’s something larger than Pluto,” I replied.

“Are you crazy?” he said. “This is the biggest astronomical discovery in the solar system in a century, and you’re going to be the one arguing that it’s not a planet?”

Uh. Yeah.

“If you call it the tenth planet, the public will be excited and engaged. If you call it the biggest not-a-planet, people will just be confused.”

I remembered Diane’s words from before Lilah was born. I gave in. The press release that went out to the world that day was titled “Caltech Astronomer and Team Discover the 10th Planet.”

I would have a lot of explaining to do, once I got some sleep.

Next up was to arrange a press conference. I called my NASA contacts and told them that I needed to arrange a press conference that afternoon to announce the discovery of the tenth planet.

Impossible, they said. The space shuttle was up at the space station with missing tiles, and people were worried about a crack-up on the way down. They were having a press conference about that this afternoon. How about Monday?

Impossible, I said. If the announcement was not made before the sun went down, almost anyone with a modest-sized telescope could point to the now publicly available positions and say they had discovered the thing.

“Did you just say tenth planet?” they asked. We set up an international press conference for 4:00 p.m.

As soon as I hung up the phone, it rang. It was an old friend from college, Ken Chang, who happened to also be a science reporter for The New York Times.

“Tell me about this big object,” Ken said.

“Which one?” I asked.

“Um, what?” he said.

He was calling about Santa/2003 EL61, of course. He had not yet received the press release about the tenth planet. I quickly told him about our big discovery and asked him if he could wait until the 4:00 p.m. press conference to get the details.

“Four p.m.? On a Friday afternoon? To announce the discovery of the tenth planet? Are you nuts?”

It seemed to be the question everyone was asking me that day. I hadn’t even realized that it was a Friday, but that was good information to try to store in my brain. And, oh yeah, that it was July.

“Friday at four p.m. on the West Coast is too late for me,” Ken said. “It’ll miss the Saturday and Sunday papers and be old news by Monday.”

I told him about the discovery. When he asked me the name of the new planet, I realized that I didn’t even know yet what the official license plate number designation was going to be (it turned out to be 2003 UB313). I told him that it had no name yet.

“Well, what do you guys call it among yourselves?” Ken wanted to know.

“Xena. It will have a real name soon, but for now we call it Xena.”

Ken chuckled and wrote it down.

Contrary to what I thought that morning, it would not get a real name soon. After Ken wrote it down that first time, Xena became its nickname for more than a year. There are many people, I believe, who still think that the object remains named Xena.

Ken Chang was right. The story did end up missing almost all of the Saturday and Sunday papers, and though the discovery was not exactly old news by Monday, it was indeed clear that Friday at 4:00 p.m. is not the right time to make a press announcement—unless, perhaps, you are announcing that you are going back to rehab, and you hope no one notices. But at least, by virtue of that one accidental phone call, the announcement of the discovery of the tenth planet hit the front page of The New York Times on Saturday, July 30, 2005.

By about noon on Friday, I had built a webpage describing Xena. It was spare but would have to do. I drove up to the Jet Propulsion Laboratory—JPL—where they had the facilities to put on a major press conference.

I can no longer put together a timeline for the rest of that day; most of the memories are simply too jumbled. I recall at some point changing shirts and shaving in the men’s room at the press building at JPL. I don’t remember a single thing I or anyone else said at the press conference, though I vaguely remember standing in front of a TV camera with a small speaker in my ear; every three minutes I was connected by satellite to some different TV show. I don’t know what I said, and I certainly don’t want to know how I looked.

I drove home late in the evening. A few minutes after arriving home, the head of the media department at JPL called me to double-check that I was all right. I remember that conversation extremely well. “I’m fine,” I said. “I’m lying on the bed and Lilah is asleep in my arms. What could be better?”

“Good,” she said. “Then would you mind doing Good Morning America on Monday morning, and they want you to bring Lilah.”

At 2:00 a.m. on Monday, Diane, Lilah, and I drove down to a Hollywood studio. Normally I would consider this hour to be thoroughly indecent, but given the round-the-clock schedule we were currently on, 2:00 a.m. was no better or worse a time than 2:00 p.m. Actually, it was better, as there was no traffic.

When I arrived at the studio, I was hooked up with earpieces again and talked about planets, old and new, with Charlie Gibson and Diane Sawyer. At the end, my wife brought Lilah over for the cameras. Two thousand miles away, in Alabama, my mother was on the edge of her seat. She already knew about all of the planet parts, so that was just filler. But it was the first time she had ever seen Lilah.

According to my calendar, the following weeks were a storm of interviews and talks and TV appearances, of which I have no memory. If you look at the records I kept of Lilah’s eating and sleeping and crying and smiling, you would not know that any of it had happened.

A week after the biggest scientific announcement of my life, it seems that all I cared about was whether or not Lilah would sleep and how frequently she would feed.

Day 31 (7 Aug 2005): Lilah is one month today! To celebrate her birthday she had a record sleep last night, almost 5 hours! It included an hour-long car ride at the beginning, which may or may not have contributed, but to top it off she then had two 3½-hour sleep sessions in a row. If you look carefully you will also note that she is, in general, stretching things out more (well, at least at night). For the past 5 days we have dropped from 10 feeds a day to 9 feeds a day. This may not seem like much to you, but it is about 45 minutes of saved time for Diane every day (or, more accurately, 45 minutes of extra sleep at night)! There was even her first 8 feed day back on Day 29 that originally passed without note. My original complaint back around Day 12, when it appeared that Lilah couldn’t distinguish between day and night, is clearly no longer valid. Night times are definitely for longer sleep periods. Thank you Lilah, thank you thank you!