In a brief article at The Washington Post, David Grinspoon and Alan Stern declare Pluto is too a planet.
Three years ago, NASA’s New Horizons, the fastest spaceship ever launched, raced past Pluto, spectacularly revealing the wonders of that newly seen world. This coming New Year’s Eve — if all goes well on board this small robot operating extremely far from home — it will treat us to images of the most distant body ever explored, provisionally named Ultima Thule. We know very little about it, but we do know it’s not a planet. Pluto, by contrast — despite what you’ve heard — is.
Click through and read the whole thing for a look at the history behind Pluto’s demotion, and a passionate defense of its planetary status. I enjoyed the sharp tone with which the authors of this post critique the decision to demote Pluto:
Even within our solar system, the IAU scientists defined “planet” in a strange way, declaring that if an orbiting world has “cleared its zone,” or thrown its weight around enough to eject all other nearby objects, it is a planet. Otherwise it is not. This criterion is imprecise and leaves many borderline cases, but what’s worse is that they chose a definition that discounts the actual physical properties of a potential planet, electing instead to define “planet” in terms of the other objects that are — or are not — orbiting nearby. This leads to many bizarre and absurd conclusions. For example, it would mean that Earth was not a planet for its first 500 million years of history, because it orbited among a swarm of debris until that time, and also that if you took Earth today and moved it somewhere else, say out to the asteroid belt, it would cease being a planet.
Shiny knife you just stabbed that definition with. Good job!