Scientists must not acquiesce to demands from Pluto Zealots


Photo Credit: Chelsea Purgahn | Daily Texan Staff

Do facts matter? Can they be objectively determined, or is truth ultimately subjective? In our fragmented society, can there be any such thing as a consensus?

These are all questions raised by the most contentious debate of our time — a debate that is often emotional and deeply personal for its participants, and one that will likely never be truly settled. I am talking, of course, about the debate over Pluto’s status as a planet.

Ostensibly, the scientific debate was settled in 2006, when the International Astronomical Union approved a new definition of the word “planet” that Pluto did not meet. But the decision was controversial, and if anything, it actually drew more attention to the Pluto debate than ever before. By demoting the former ninth planet from the sun, the IAU incubated the cult of Pluto enthusiasts and sympathizers to an extreme level. At the end of the year, the American Dialectical Society declared “plutoed,” which means demoted or devalued, the word of the year. Multiple state legislatures moved to voice their solidarity with a tiny frozen rock orbiting the sun at a distance of 3.67 billion miles and occasionally crossing Neptune’s orbit.

Since then, the debate has continued to flare up every few years. In 2014, the Harvard-Smithsonian Center for Astrophysics held a debate on Pluto’s status and let the audience (which was not composed of experts) vote at the end. They made headlines by voting in favor of making Pluto a planet again.

And two weeks ago at the Lunar and Planetary Science Conference in Houston, Kirby Runyon, a Johns Hopkins University earth and planetary sciences doctoral student, presented his case for a new definition of a planet that would include Pluto — as well as more than 100 other celestial objects. The five currently recognized dwarf planets would qualify as regular planets under this definition. So, as a matter of fact, would most moons, including Earth’s.

Which, come on. How much are we willing to sacrifice just to save Pluto? One of the best arguments against making Pluto a planet is that indeed, doing so would probably require a definition like this, accepting dozens of new objects into our solar system as planets. In fact, there are likely thousands of undiscovered Pluto-like rocks orbiting the sun in the distant Kuiper Belt. Should they all become planets?

As Runyon notes, “there is a psychological power to the word ‘planet’ that helps people realize it’s an important place in space.” But there’s also psychological power in the number of planets we choose to recognize. Imagine forcing schoolchildren to learn the names of dozens, potentially hundreds of planets. Imagine mnemonic devices that stretch for paragraphs and pages.

It wouldn’t work. The question of Pluto isn’t just a scientific one — it’s a linguistic one, and also a pedagogical one. There is, of course, no objective definition of a planet. But whatever definition we agree on should be one that makes space intellectually accessible to ordinary people. An informed public interest in space is worth the cost of a single former planet.

Groves is a government sophomore from Dallas. He is a Senior Columnist. Follow him on Twitter @samgroves