How I Killed Pluto and Why It Had It Coming (28 page)

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

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 the 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:

“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:

I almost felt bad enough to want to give in. I didn’t object to dwarf planets being considered planets, which was all he was talking about. But I did object to the other planets being termed “classical planets.”

For the anti-Pluto side, a British astronomer stood up and spoke:

Sadly, even though I was all in favor of rejecting the resolution, I found almost none of the arguments compelling. Who cared what the consensus was on Tuesday? The final vote was today! And really, if the concepts were significant, wasn’t it more important to make sure to get them right than to worry about the precise wording of the resolution? Besides, would it matter if there were eleven or more planets? It wasn’t the number that mattered, it was getting the concepts right. I realized that I wouldn’t have minded if there were “major planets” and “dwarf planets” instead of “classical planets” and “dwarf planets.” I guess my own version of pickiness was just as bad as anyone else’s.

The vote was called. If the resolution passed, Pluto would be a planet again, and Xena would officially be part of the club. Chad, David, and I would be the only living discoverers of a planet in the world. At least for now. And still I didn’t want it to happen.

“All in favor of the resolution?”

Astronomers in favor of 5B—in favor of repromoting Pluto—held up their yellow cards. There were many. The counting took a few minutes.

“Mister President, we report ninety-one votes in favor.”

That didn’t seem like enough, but I couldn’t tell from the tiny webcast precisely how many astronomers were there in the auditorium.

“All opposed to the resolution?”

Astronomers opposed to 5B, who wanted to firmly cap the solar system at eight planets, held up their cards. A sea of yellow filled the auditorium, which immediately erupted in applause.

“I think, Mister President, a further count is not honestly needed.”

“Then it’s clear that Resolution 5B is not passed.”

At that point it was final. And I said to the assembled press: “Pluto is dead.”

The cameras whirred; correspondents talked into their microphones; on a screen on the other side of the room I could see myself on some local television station repeating, like an echo, “Pluto is dead.”

Most of the remainder of the day was a blur of interviews, condolences, and congratulations. That afternoon I made my way to the studio of a radio station, where I was scheduled to be on a call-in program broadcast throughout Los Angeles. When I showed up at the studio, they told me that another astronomer would be calling in as a guest.

Great, I thought. Another guest would help me to stay focused and coherent.

When we went live on air, I suddenly realized that the astronomer was none other than the member of the once-secret planet-definition committee, live from Prague! It had been an even longer day for him than it had been for me.

He seemed tired, and he definitely didn’t seem happy. He talked about how he thought the vote had done a disservice to astronomy. I said I thought astronomy had done a great service to the world.

He said that he was sad that no one would ever again be able to discover a new solar system planet under the current definition.

“You know,” I said, over the radio to him half a world away, “when you tell me that no one will ever discover a planet again, I just take that as a challenge.”

Over the course of the radio show, we both answered questions
from callers. It was becoming clear that the idea that Pluto was no longer a planet was not going to be an easy sell.

Throughout the hour, the host collected suggestions for a new mnemonic for remembering the order of the planets. Some gave a slight modification of the previous standard—My Very Educated Mother Just Served Us Nine Pizzas—by turning “Nine Pizzas” into “Nachos” or into “Nothing,” which was a bit funnier. But the best mnemonic, and the one that I still tell people to use to this day, sent in by an anonymous listener, sums up the feelings that would envelop much of the world over the next days, weeks, and months:

Mean Very Evil Men Just Shortened Up Nature.

Keeping Pluto dead has taken a lot of work.

In the days, months, and years since the decision was made, I’ve been accosted on the street, cornered on airplanes, harangued by e-mail, with everyone wanting to know: Why did poor Pluto have to get the boot? What did Pluto ever do to
you
?

It is at these moments that I am most happy that astronomers ignored my initial advice to simply keep Pluto and add Xena and forget about a scientific definition. I am thrilled that astronomers instead chose to put a scientific foundation behind what most people think they mean when they say the word
planet
. They don’t mean “everything the size of Pluto and larger,” and they certainly don’t mean “everything round.” Instead, when people say “planet,” they mean, I believe, “one of a small number of large important things in our solar system.”

My job is just to explain the solar system as it actually is. People, I think, will then realize themselves that Pluto is not one of these large important things in our solar system.

Here is what I say to people:

Many astronomers, tired of the endless debates before and after the demotion of Pluto, will tell you that, in the end, none of this matters. Whether Pluto is a planet or not is simply a question of semantics. Definitions like this are unimportant, they will say. I, however, will tell you the opposite. The debate about whether or not Pluto is a planet is critical to our understanding of the solar system. It is not semantics. It is fundamental classification.

Classification is one of the first processes in understanding something scientifically. Whenever scientists are confronted with a new set of phenomena, they will inevitably, even subconsciously, begin to classify. As more and more things are discovered, the classifications will then be modified or revised or even discarded to better fit what is being observed and what they are trying to understand. Classification is the way that we take the infinite variability of the natural world and break it down into smaller chunks that we can ultimately understand.

So how should we classify the solar system? It’s hard, because we are sitting in the middle of it and have known planets our whole lives. But let’s try to do it from the perspective of someone who has never seen a planet before. Imagine that you are an alien who has lived your whole life on a spaceship traveling from a distant star to the sun. You don’t know that planets exist. You don’t even have a word for planet in your language. All you know is your spaceship and the stars you can see surrounding you. The sun—which originally looked like any other star—now gets brighter and brighter as your destination nears.

As you start to stare at and wonder about the sun, you suddenly notice that—wait!—the sun is not alone! You see that there is something tiny right next to it. You’re excited beyond alien words. As your spaceship gets closer and you look even
more carefully, you suddenly realize there are
two
tiny things next to the sun. No, three. No, four!

You have just found the things that we call Jupiter, Saturn, Uranus, and Neptune: the giant planets. From your perspective, still quite far from the solar system, they look tiny and so close to the sun as to be barely distinguishable. You don’t have a word to describe them, so you make one up in your alien language: Itgsan.