Mike Brown

by How I Killed Pluto;Why It Had It Coming

  I did not sleep well that night.

  The next morning, I went to the village of Eastsound, where I knew I could get freshly brewed coffee and a freshly flown-in newspaper. On the front page, a headline screamed, “Three New Planets Added to Solar System.” A beautifully prepared graphic—courtesy of the IAU—showed the new solar system with the twelve planets all in place. The article prominently featured quotes of mine from previous interviews about the new planet Xena.

  I felt sick to my stomach.

  This was it. Astronomers had taken a beautiful and subtle solar system and turned it into a cartoon. And the cartoon was wrong.

  I went back to the house and called the people at media relations at Caltech and told them where to find me. I hung up the phone and waited for two minutes before it rang.

  I spent most of the next twelve hours, and indeed most of the next week, on the phone talking to the press about the solar system, planets, and why the IAU’s proposed definition was fatally flawed, and explaining why Pluto—and Xena—should really not be considered planets.

  At first the reporters were shocked. They were calling to get quotes from the most newly minted planet discoverer about how fabulous all of this was. Instead I was telling them that everything they had heard from the IAU the day before made no sense. Suddenly there was a controversy. My phone kept ringing.

  Lilah developed a new sign, which either meant “Daddy” or simply meant “phone,” I could never tell. Whenever she saw an object of the right size, she would pick it up and immediately hold it to her ear and then point at me.

  Astronomers around the world picked up on some of the silly implications of making Charon a planet simply by virtue of the location of the center of mass of the orbit. In the middle of one phone interview, it suddenly occurred to me that the center of mass of the sun and Jupiter lies outside the sun, so by IAU logic, Jupiter should not be considered a planet since it doesn’t really go around the sun. Another astronomer sent an e-mail showing that if a massive moon were on an elongated orbit, the center of mass could be inside the planet during part of its orbit but outside the planet during other parts of its orbit, meaning that, according to the IAU, that moon would switch back and forth between being a planet to being a nonplanet during the course of its orbit. And a few days later, courtesy of a fabulous press release by Greg Laughlin, an astronomer at the University of California Santa Cruz, the newspapers explained that because our moon is slowly moving outward, away from the earth, in a billion years or so it will have moved so far away that the center of mass of the earth-moon system will lie outside the earth. Suddenly: boom! The moon will officially be a planet. It would be a day to celebrate.

  I wasn’t in Prague, so someone else will have to tell the details of what actually happened there. What I do know is this: Astronomers there, who I had been told were going to go along sheepishly with this mess of a proposal, revolted.

  The revolting astronomers, who grew to be a sizable fraction of the astronomers present, made it quite firmly known that they would not support the secret committee proposal. The only proposal they would support would be one where Pluto was put in its logical—rather than emotional—place. Pluto, Charon, Ceres, and my own Xena would all have to go. The press, and indeed the astronomers in Prague themselves, were quite amused by the fact that one of the most vocal supporters of demoting Pluto, Charon, Ceres, and Xena was the guy who had the most to personally gain from Xena being a planet: me.

  My phone calls with the press and conspiratorial e-mails with astronomers in Prague continued for most of two weeks, first from Orcas and then from Pasadena, after we returned home from our vacation. Everything was building toward the final afternoon of the final day of the IAU meeting, when the deciding vote on the definition of the word planet would finally be held.

  The vote was going to be broadcast live around the world, and I was going to host a packed media event to watch it, even though afternoon in Prague was before dawn in Pasadena. By 5:00 a.m. the news crews and I were setting up in a room usually taken up by press conferences about the latest southern California earthquake. The vote on the resolution that could completely change the way people looked at the solar system was slated to take place in under an hour. That morning, the astronomers in Prague had awakened to read the final wording of the resolution to be voted upon. And the wording mattered. Cosmic distrust in Prague was running so high at this point that many assumed that the clearly pro-Pluto secret committee would attempt to subvert the clearly anti-Pluto-as-a-planet majority by sneaking in wording that would keep Pluto no matter what the vote.

  Sitting at a desk in the earthquake room in Pasadena in front of the still assembling press, I projected onto a large screen a just-posted copy of the precise wordings of the resolutions, which I had found at the meeting website. Along with the news crews and, by now, a growing crowd of interested onlookers from the Caltech community, I read, for the first time:

  Resolution 1: Precession Theory and Definition of the Ecliptic

  I only then realized that there was more on the agenda than Pluto and that this morning might be much longer than anticipated. While I know what precession theory is, and I even knew the definition of the ecliptic, I wasn’t even slightly interested in knowing the precise definition being proposed here—and neither were most, if not all, of the astronomers in Prague.

  Resolution 2: Supplement to the IAU 2000 Resolutions on reference systems

  Yawn.

  Resolution 3: Re-definition of the Barycentric Dynamical Time, TDB

  I must have missed the original definition.

  Resolution 4: Endorsement of the Washington Charter for Communicating Astronomy with the Public

  I began to understand why, until now, no one had ever gone to the voting part of these meetings.

  Resolution 5A: Definition of “planet”

  Finally! I quickly read through the definition. Though confusingly worded and perhaps poorly thought through (not surprising, given that the final wording had probably been hammered out late in the night), the definition led to reasonable results. It even included a footnote that clearly stated, “The eight planets are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune,” and that Pluto and Xena, along with the asteroid Ceres, were to be called “dwarf planets,” a term no one had ever heard before. The resolution was clear to point out that dwarf planets are not planets, which I found an odd use of the English language.

  The first question from the press: “Dwarf planets are planets, right?”

  No, I explained. The resolution was pretty clear. There are eight planets; dwarf planets, of which there might be hundreds, were clearly not planets.

  But how could something be called a dwarf planet yet not be a planet? they wanted to know. A blue planet is a planet, right? A giant planet is still a planet. A dwarf tree is still a tree. How can a dwarf planet not be a planet?

  Such is the beauty and frustration of definitions, I suppose. But I agreed that it seemed a poor choice, and an odd phrase to make up out of the blue. Something seemed suspicious. Still, the resolution was clear: There were only eight planets. If the astronomers voted yes on Resolution 5A, Pluto was clearly dead.

  “But what about Resolution 5B?” someone asked.

  I hadn’t gotten around to reading that one yet. I turned to the screen.

  Resolution 5B: Definition of Classical Planet

  Huh? “Classical” planet? It was the Pluto escape clause! Resolution 5B simply changed the word planets in the previous resolution to classical planets. There would now be eight classical planets and four dwarf planets. With the quick addition of one word—classical—in front, dwarf and classical simply became different but equal subsets of the overall category of planets. Suddenly, dwarf planets were planets after all. The committee had indeed tried to sneak Pluto back in. The odd phrase dwarf planet had been invented in the previous resolution to allow the possibility that Pluto could rise from the underworld to live again.

&
nbsp; Like the previous resolution, this definition was also muddled. Why “classical” planets? Shouldn’t the phrase classical planets refer to those known in the classical world? In Greek and Roman times, there were seven planets: Mercury, Venus, Mars, Jupiter, and Saturn, and also the sun and the moon. Earth was not considered a planet, since it was the center of the universe. Uranus, discovered in 1781, and Neptune, discovered in 1846, were a few thousand years postclassical. Calling the largest eight planets “classical” made no sense at all.

  I explained to the journalists in the room the now overly complex possibilities of the vote’s outcomes and what the fate of Pluto would be in each case. Finally, the question came: “Do you think Pluto should be a planet?”

  I sighed; it would have been thrilling to be considered the discoverer of a planet. “No,” I responded. “Pluto should not be a planet. And neither should Xena. When Pluto was discovered in 1930, there was nothing else good to call it, but by now we know that it is one of many thousands of things in orbit out past Neptune. The vote today would rectify an understandable mistake made in 1930. Going from nine planets to eight planets would be scientific progress.”

  By 6:00 a.m. in California it was 3:00 p.m. in Prague, and the assembly was about to start. We were going to eavesdrop on the vote courtesy of a jumpy, low-resolution webcam broadcasting the event. I found the link for the webcast, clicked on it, and projected it onto the oversized screen behind me for everyone to see. It ended up filling an area of about one square foot. If you looked closely, you could see inch-high astronomers filing into the room.

  Much of the next hour is a blur in my memory. After we watched an Austrian barbershop quartet there were nine hundred new members to be voted in and the first four resolutions to sit through. It would be a long morning. I muted the sound and opened the floor to questions, of which there were many. I can’t remember a single one. On the tiny video, we could see people making speeches and raising yellow cards to vote on Barycentric Time. Someone finally brought me coffee. The first four resolutions quickly passed, with little discussion and without a single vote of no.

  Finally the text for Resolution 5A appeared on the screen; we quickly unmuted the video stream and listened in. The once-secret committee, now beaten down by other astronomers, read and explained the resolution. The floor was opened for comment. One by one astronomers raised their hands and were passed a microphone. Here are some excerpts from the scientific debate of the learned astronomers:

  Resolution 5A, Section 2 starts “a dwarf planet.” Could you put dwarf planet in inverted commas, put quotation marks around dwarf planet? It is a definition. It should be in quotation marks.

  The press assembled with me chuckled.

  At the beginning of 5A we talk about planets and other bodies. That could be taken to include satellites. We didn’t mean it to include satellites but it could be read to mean satellites.

  The assembled press looked at me to see if this was significant. I shrugged my shoulders.

  I suggest in part 3 of 5A where it says “all other objects” you insert “except satellites” and thank you to the people who suggested those points. I think they are a great improvement.

  Chuckles all around.

  The order in which we have the resolution printed is not the order in which some countries do business. In some countries you do the amendments first and then vote on the substantive resolution.

  More laughs.

  “Wait!” I said, quickly turning the volume down. “This comment is really important. This part is insidious. This is deliberate! 5B, which is an amendment to 5A, is voted on after 5A. 5A, which says Pluto is not a planet, will have general support, and then 5B will get snuck in to subvert the intentions of 5A. And no one seems to care.”

  But no one other than me seemed to grasp the enormity of the conspiracy at hand. Sure, perhaps I was a bit on the exhausted side at this point and inclined to believe that the secret committee had also conspired to assassinate Abraham Lincoln, Archduke Ferdinand, and Julius Caesar, but just because I was being paranoid didn’t mean I was wrong.

  I turned the volume back up, and we were back to punctuation:

  The inverted commas look right when you see them, but you don’t speak them. Could you not think of a new word which doesn’t exist in the dictionary so that it doesn’t have any baggage, and instead of calling it “dwarf planet,” use some word, since it’s an entirely new thing.… What you need is a new word rather than combination of old words; but a planet is a planet and so is a dwarf planet from a schoolmaster point of view.

  I was feeling punchy and kept interjecting. “Yeah, he is right,” I muttered. “ ‘Dwarf planet’ is a dumb phrase. For years we’ve called things like Pluto and Xena ‘planetoids’—planetlike. That was a perfectly good word yesterday. But they’re trying to be sneaky, they are. ‘Dwarf planet’ is dumb, but they need it so Pluto can become a planet with 5B.”

  The press at this point began to think that I was perhaps as crazy as all of the astronomers arguing over punctuation in Prague.

  A question from the astronomical floor: “How does Charon fit?”

  Right. At this minute there is confusion about Charon. If we pass 5A, Charon is not a planet. Right now I think there is confusion.

  Someone else interjected: “It’s a satellite! As long as it remains a satellite, it’s out with this resolution.”

  Comment: “A point of clarification for me: Is a dwarf planet considered a planet?”

  “That is Resolution 5B.”

  “In 5A a dwarf planet is not a planet?”

  “Right.”

  In perhaps my favorite exchange of the very early morning, the question “Do I understand correctly that we are not anymore entitled to use the word ‘planet’ for planets around other stars?” elicited the response: “Are you referring to floaters, sir, or are you talking about extrasolar planets?”

  Floaters? All I could think of were those little spots that you can sometimes see floating in your eye. I never heard the answer because I was at this point just shaking and shaking my head wondering how much longer this could possibly go on.

  From a pedant: “Last Friday you mentioned we are not voting on the footnotes, but now you are referring to the footnotes. So are we voting on the footnotes or not?”

  Response: “We were at one point trying to say that the footnotes are not part of the resolution. I think that position is not tenable; it is a stupid position. Therefore the footnotes are now part of the resolution.”

  Out of nowhere: “There is so much left in the resolution to common sense that I would propose to drop the entire resolution and leave Footnote One.”

  That was just about the best comment of the morning. The astronomer was right: The resolution that came up with a definition was so poorly written and vague that it would have been clearer to simply say what Footnote 1 said: The planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Everything else was just an attempt to explain why—and a poor attempt at that.

  The commenting went on for another hour before, mercifully, someone called for a vote. Those in favor of Resolution 5A, which would create eight planets and an unspecified number of dwarf planets, were asked to hold a yellow voting card in the air. The room was filled with the color of the sun. There was no need to count. Resolution 5A passed with overwhelming support. Pluto was, correctly, no longer to be classified with the other eight planets. It was a moment that I never thought I would see in my lifetime.

  The press in Pasadena were aghast and astounded and excited. They were ready to hit the “send” button to upload their stories.

  “No no no, wait!” I told them. There was still Resolution 5B! This was where the conspiracy would happen! This was where the secret committee would subvert the will of the astronomical community! “Wait and watch!” I told them.

  We watched. And then the most amazing thing happened. In the still-too-early fog of a not-enough-coffee morning in Pasadena, with th
e press watching astronomers half a world away, awaiting the secret sign to the pro-Pluto brotherhood to emerge to protect the god of the dead, I saw, instead, the moderator of the meeting stand up and make a few simple statements that put everything in precisely the right place. Where were the conspirators? Where were the daggers? Maybe I was in need of sleep.

  Here is what she said:

  5B involves inserting one word. Surely not a serious matter. However. For the benefit of non-astronomers present [but, really, isn’t she doing this for the astronomers?], I want to do a bit of teaching, which demonstrates that resolutions are non-linear, and small changes have big effects. Excuse me while I dive under the table. [She pulls out a large beach ball, to represent planets, and a stuffed dog—Pluto!—to represent, well, Pluto.]

  At the moment, right now, having passed resolution 5A, we have planets, the eight that are named [points to beach ball], we have dwarf planets [points to stuffed Pluto], and we have small astronomical bodies that are non-spherical. If we reject everything else this afternoon that is what will stand. If, however, we add the word “classical” to this group [beach ball], then we have adjective planets [beach ball], different adjective planets [stuffed dog], and it could be argued that what we are doing is creating an umbrella category called planets under which the classical planets and the dwarf planets fit. And if we do this then that [pulls out umbrella, puts beach ball and stuffed Pluto under it; audience erupts into applause] pertains.

  “Who is that?” someone in the press asked me.

  The speaker was Jocelyn Bell, who was widely considered to have deserved a Nobel Prize in 1974 for her discovery of pulsars. I didn’t need to speak; I just smiled. No conspiracy was going to happen on her watch. Although I wasn’t sure what the outcome would be, astronomers were going to decide based on knowing exactly what they were voting for.

  Only two comments were allowed. The first, in favor of the pro-Pluto resolution, was from the member of the once-secret committee who had called and told me that the committee’s original definition, now dead, had been assured of passing. Wearing a tie with planets on it, standing in front of the auditorium, he looked tense, angry, and maybe a little sad. He made his case: