Review 71: The Pluto Files

The Pluto Files by Neil deGrasse Tyson

What was the biggest story of 2006? The arrest of the shampoo bombers in England? Small fries. The first World Baseball Classic? YAWN! The death of Don Knotts? Nothin'.

No, as interesting as they were, none of these generated nearly as much public interest and argument as the much ballyhooed "demotion" of Pluto by the International Astronomical Union in August of 2006. Poor little Pluto, hanging out there on the edge of the solar system, got bumped down to "Dwarf Planet," rousing much ire from people all across the United States. And, in a way, Neil deGrasse Tyson bears some responsibility for it.

To be fair, stripping Pluto of its designation as a planet was never on his agenda. No matter what angry elementary school students may have thought, Tyson had no beef against Pluto. It was just that Pluto had the bad fortune to be an oddball planet, and Tyson was working on the redesign of the Rose Center for Earth and Space in the American Museum of Natural History in New York. Whether he wanted to or not - and I'm pretty sure he didn't - he became the public face of this issue, one which gripped the country.

That in itself is weird. Americans are not the most scientifically literate of people. Sure, we like to use the fruits of science, but most people don't really pay attention to things like astronomy unless it's a shuttle launch or a pretty Hubble picture. What's more, the public in general has never really gotten involved in matters of taxonomy. If you went up to someone and said, "Hey, the scientific community is thinking about revising the nomenclature regarding the classification of anaerobic bacteria," they'd probably just walk away swiftly, looking back a few times to make sure the crazy person isn't following them. But tell them that the IAU is planning to demote Pluto, and what you have is a firestorm.

This book is not so much about Pluto itself, but our relationship with that weird little ball of ice and rock. Tyson takes us through our history with Pluto, from its discovery back in 1930 to its demotion in 2006, and tries to figure out just what it is that has endeared it so to the American public.

One possibility, of course, is the fact that Pluto was an American discovery. Percival Lowell was the one to start the hunt, and Clyde Tombaugh finally found it. While the name was suggested by a teenage British girl, everything else about the discovery of Pluto was American, and that was a point of pride. There were only three non-Classical planets in the heavens, and we had claim to one of them. So even if the average American doesn't know the history of Pluto's discovery, we still have a certain love for it.

Despite its diminutive size, Pluto has loomed large in the American imagination. Perhaps there's something of the underdog love in there, too. Americans love to see the little guy win, and if you look at a lot of the pro-Pluto artwork from 2006, the theme of big planets ganging up on a little one was very popular. As odd as this perception might seem from a scientific standpoint, I think a lot of Americans were supporting Pluto because it was being pushed down by The Man, as it were.

And so the country went a little nuts. Newspapers, blogs, websites - even sports reporting got in their digs on the Pluto controversy. There was something for everyone in this story, and everyone who could manage a Pluto reference did so with gusto. It was a mixed blessing, to be sure - the American public was finally excited about astronomy, but it was the excitement of a bar fight, rather than the highbrow intellectualism that many astronomers might have preferred.

What was also interesting about this book was the look at the professional arguments that went on as well. Dispelling the dispassionate image of the astronomer, professionals got really worked up about this, on both sides of the issue. Grown men and women, many of whom were well-versed in many aspects of astronomy, spoke passionately about Pluto. Some called on our sense of tradition and cultural memory, acknowledging that while Pluto may be an oddball, he's our oddball. Others were more than happy to throw Pluto into the Kuiper Belt with the other icy mudballs.

So often, Science is assumed to be some monolithic entity that describes the world with a unanimity of voice. It is supposed to be dispassionate and rational, and we don't really think about the reality of scientific progress. To use the analogy often given to marriage, science is like a duck - stately and sure on the surface, but with a whole lot of work going on down below. The history of science is full of more passion, debate and anger than you might suspect. In order to decide the issue, symposia were convened, meetings were held, and finally the International Astronomical Union was forced to do something that had never occurred to anyone before: precisely define what is and is not a planet.

In case you're wondering, the definition is quite simple: It has to orbit the sun, be big enough to have attained a spherical shape, and it has to have cleared out its orbit. Pluto fulfills the first two requirements, but badly fails the third. Therefore, it is not a planet. They created a new designation: dwarf planet, including Ceres in the asteroid belt and Haumea, Makemake and Eris out past Pluto. The public may not like it, but that's how it is.

Tyson points out that this is not the first time we have done such a reclassification. With the discovery in the mid-19th century of objects orbiting between Mars and Jupiter, a new class had to be invented in order to keep the number of planets from rocketing into the thousands - and so asteroids were born. The Pluto case is quite similar. Long after Pluto was discovered, more objects, similar in nature, were discovered nearby - some even bigger than Pluto was. The region of rock and ice was named the Kupier Belt, and if Pluto were discovered today, it would most certainly be named as part of it. As much as it pains me to say it, the decision to reclassify Pluto was the right one. At least Tyson and I have revised the Planet Mnemonic the same way: My Very Educated Mother Just Sent Us Nachos.

The rise and fall of Pluto is an interesting story, and a lesson for science educators. No matter how bad it may seem for science in the United States, people can still be surprisingly passionate about scientific topics. It's also a warning against resistance to change. With all that we are learning about the Solar System, to just rattle off a list of planets and be done with it is insufficient. There are so many other ways to look at it now, so many ways to group the hundreds of bodies out there, that perhaps Pluto is more comfortable out with the other Trans-Neptunian objects. With its own kind, as it were, instead of being shoehorned in with eight other guys that it doesn't really have anything in common with.

Ultimately, of course, Pluto doesn't care what we call it. That point was often made on both sides of the argument, and they're right. We could call it Lord Snuggypants the Fourth and it would keep doing what it does out there in the cold and the dark. But it's important for us, and not just because science needs things to be organized so we know what we're talking about. Being able to reclassify Pluto is an indication of the breadth of our knowledge - had we not made such progress, Pluto's classification would never have been in doubt.

The "demotion" of Pluto is a sign of our amazing achievements over the last eighty years. We have not lost a planet - we have gained understanding. So in the end, the Great Pluto Debate is one that we should look back upon fondly.

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"It's always a little scary when the person who hired you calls you up and asks, "What have you done?!"
- Neil deGrasse Tyson, The Pluto Files
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Neil deGrasse Tyson at Wikipedia
The Pluto Files at Wikipedia
Pluto on Wikipedia
The Pluto Files on Amazon.com
Neil deGrasse Tyson's homepage

Laurel's Pluto Blog