How I Killed Pluto (and Why It Had it Coming)
© 2010 Mike Brown
Is that not the greatest title ever? How I Killed Pluto and Why It Had it Coming is the tale of Pluto’s rise and fall as a planet, delivered by an astronomer who discovered a series of objects in the Kuiper Belt in the early 2000s. The discovery of one object larger than Pluto forced the International Astronomical Union to come to a decision: what, exactly, is a planet? The resulting definition would famously demote Pluto to ‘dwarf planet’, in the company of Ceres and Eris. Brown’s confession argues that the 2006 decision wasn’t the first time the concept planet had to be redrawn, and that Pluto’s status as a planet was tenuous to begin with. Regardless of one’s own astronomical convictions, How I Killed Pluto is popular science at its best,
What is a planet? School children may learn that planet stems from the Greek word for wanderer, given that Earth’s neighbors were seen to move through the sky independently of the ‘rest’ of the stars. To the Greek mind, ‘planet’ encompassed not only ‘our’ planets, but the Sun and Moon as well — for they, too, were celestial roamers. Astronomical knowledge grew throughout the medieval era, however, arriving at a worldview in which ‘planet’ meant a body that orbited the sun — and included the Earth. New discoveries continued to challenge the mental map, like a couple of small bodies between Mars and Jupiter. Initially regarded as planets, they would eventually be given their own distinct category — asteroids — once it realized there were not one or two bodies out there, but scores of them. The same would had proven true for Pluto, Brown argues, had we realized how much more was out there. Instead, the limits of our technology left us ignorant of most of Pluto’s neighborhood, and without context for its placement. For seventy years, Pluto enjoyed a status that it didn’t quite merit. As much as Brown would have liked to have taken credit for discovering the “tenth planet”, thinking as a scientist he couldn’t quite stomach it. The modern map of the solar system includes distinct groups of objects: the terrestrial planets, an asteroid belt, the great gas giants, and the far-circling Kuiper belt around us. Viewed objectively, how could a minuscule dot plucked from the Kuiper belt be considered in the same category as Jupiter, but not the others?
How I Killed Pluto succeeds in many levels. As a pop science piece, it delivers a sense of how science works. Not only does Brown’s account cover the day to day work of a modern astronomer — poring through computer screens, analyzing the data for what the programs missed — but the kind of organized, critical thinking required to piece together order from chaos. Brown’s passion for collecting and organizing data is, in a word, pervasive; when his daughter is born (in the same year that he discovered several bodies that were pending official names) , she becomes a science project. He charts her feeding and sleeping periods, attempting to figure out if one method of feeding is more effective than another, and creates graphs in attempt to see patterns. (He is allowed to get away with this by virtue of being married to another scientist, one whom he met in the basement of a telescope). Brown is an excellent communicator, using analogies that work without feeling forced. He is an author who a reader like to hear talk, brimming with both passion and intelligence.
Brown’s memoir was an utter delight to read, and frankly makes me fear for the rest of the year: things can only go down from here.