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How Neil DeGrasse Tyson Put Pluto And Himself In The Planetary Dog House

Reviewed by Darci Snowden

The Pluto Files

by Neil DeGrasse Tyson

194 pp, W. W. Norton & Co., 2009

In 2015, New Horizons will be the first spacecraft to make a close encounter with Pluto. New Horizons is the fastest spacecraft to ever fly, and it will be near Pluto for just a few minutes before continuing its journey. It isn't much, but it's the best we can do for poor Pluto: so small, so far away, and so no longer a planet.

In The Pluto Files, author Neil deGrasse Tyson takes us on an amusing journey through some recent planetary history. Pluto became the nation's celestial sweetheart after its discovery in 1930 by American astronomer Clyde W. Tombaugh. When Pluto's status was redefined in the more complex solar system we know today, America had a very spirited reaction.

Tyson is a Harvard and Columbia educated astrophysicist who has written several popular books and is the host of Nova's ScienceNow. He often can be seen on the couches of Jay Leno, Jon Stewart, and Stephen Colbert. Currently, he holds the Fredrick P. Rose Directorship of the Hayden Planetarium in New York City.

While designing exhibits for the Hayden Planetarium, part of New York's American History Museum's Rose Center for Earth and Space Sciences, Tyson and his colleagues were hesitant to group tiny, icy Pluto with the super gas giants Saturn, Jupiter, Neptune, and Uranus or the rocky inner planets Mercury, Venus, Earth and Mars. Instead Pluto was grouped with the other icy bodies that circle the Sun beyond Neptune, known as the Kuiper Belt Objects.

On February 22, 2001, almost a year after the Rose Center opened, a headline appeared on the cover of the New York Times:

"Pluto Not a Planet? Only in New York." In Tyson's own words his, "life would never again be the same."

Tyson, one of the most well-known and popular astrophysicists of our time, became a hated enemy of Pluto lovers of all ages and authorities.

He received packets of letters from school kids, showing extreme preference to the pint-sized planet. Emmerson York, a third-grader from Pennsylvania, didn't even give Tyson chance to explain himself: "I think Pluto is a planet. Why do you think Pluto is no longer a planet? I don't like your answer!!!" Madeline Trost, of Florida, was also displeased: "Some people like Pluto. If it doesn't exist then they don't have a favorite planet. Please write back, but not in cursive because I can't read in cursive."

Tyson's stance on Pluto was finally vindicated on August 24, 2006 when Pluto lost its full-blown planet-hood on a technicality. In a controversial vote taken on the last day of a week-long conference, members of the International Astronomical Union voted that a planet must possess the following traits: (1) it must orbit around a star, but not orbit around another, larger body, (2) it must be massive enough to form a sphere under its own gravitational force, and (3) it must have cleared its orbit of debris. Compared to the other planets Pluto utterly fails the third criteria. Pluto's mass is only 0.07 of the remaining mass in its orbit; Earth, on the other hand, is 1.7 million times more massive than the other objects in it orbit. Pluto was demoted to a dwarf planet.

In The Pluto Files, Tyson delivers sharp, juicy exchanges between famed scientists, hilarious letters from kids, and bizarre pieces from popular media. Tyson also includes bite-sized chunks of science. This description is typical of Tyson style, "...Earth, as a cosmic object is remarkably smooth; if you had a giant finger and rubbed it across Earth's surface (oceans and all), Earth would feel as smooth as a cue ball." Tyson has a gift for communicating science to the masses, and nothing in this book is inaccessible to the nonscientist.

The Pluto Files is not without its problems. The extremely casual writing style and the abundance of illustrations and comics gives it a children's book feel, which doesn't jibe well with the fact that Tyson, for some reason, brought up a Disney character's sexual desires in the first chapter. Cringe! In fact, the first chapter is by far the most problematic; here the text bumbles along with too many random, loosely Pluto-related factoids. Keep reading; it gets better.

This book is not going to convince the hard-core plutophile that Pluto is not a planet. That debate will likely rage on, at least until New Horizons sends back its first pictures, making Pluto more than just a fuzzy ice ball. Perhaps, New Horizons will observe something that will make even Tyson reconsider Pluto's status among the spheres.

Until then, Tyson makes a good point: instead of clinging to our notion of nine planets and an educational scheme that mostly involves memorizing their names in order, why not focus on their physical properties? Pluto is round, small, mostly made up of ice, and has three moons, one of which is almost as large as itself. Isn't that all that really matters?

Darci Snowden is a graduate student in the Department of Earth and Space Sciences at the University of Washington, Seattle.


Pluto and its three moons taken by the Hubble Space Telescope in 2005. Image: NASA, ESA, H. Weaver (JHU/APL), A. Stern (SwRI) and the HST Pluto Companion Search Team,

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