The status of Pluto as a planet is back in the news.
According to news outlets that care enough to keep reporting science news (though displays of even moderate amounts of intelligence have fallen out of favor in our current society), scientists are considering a redefinition of the word “planet,” partially to align the definition to include bodies of similar physical characteristics, and partially, I think, to include Pluto back in the definition.
Per the current definition, Pluto is not a planet because it fails to clear its neighborhood of other bodies. Hence a new classification – dwarf planet – was created to classify Pluto and other bodies like it.
I can see why some would complain about demoting Pluto to dwarf planet status. I have an old snowblower that blows snow about one foot from its discharge chute. As I attempt to plow my driveway, all I can do systematically move snow in rows one foot closer to the edge, until the layers of blown snow from previous rows pile onto existing snow. After a few rows, the snow has piled so deep the blower can no longer move. In this regard, the snowblower fails to clear its neighborhood – my driveway – of snow. But I have not changed its status to one of “not a snowblower” simply because it has failed to clear my driveway. It is still a snowblower, just a lousy working one.
On the other hand, I have added modifying adjectives to its status, such as “crappy snowblower” and “f#*%ing snowblower,” so I see how the Pluto modifier “dwarf planet” applies. The longer my crappy snowblower sits in the garage unused, the less I will think of it as “crappy snowblower,” and the more I will change its status to “piece of junk.” When I will need to walk around it to get my lawn mower later this spring, it will become a “piece of junk in my way.” When I want to get rid of it, I'll know who to call, and it will not be 1-800-Got-Snowblowers.
If one thinks about it, “planet” is not the smallest classification for things we think of as planets anyway. The big bodies orbiting the sun are further subdivided into “rocky” planets like Mercury, Mars, and Venus, and “gas giants” like Jupiter and Saturn. We even go so far as to classify “life-supporting planets” of which there is only one. So why then the big stink about referring to Pluto as a “dwarf” planet? Perhaps the ire is attached to the word “dwarf” as if Pluto were somehow stunted in its growth. Perhaps the complainers would be less irate if bodies like Pluto were referred to instead as “cute” planets. After all, as the New Horizons space probe has shown, Pluto is kind of cute with that big ol' heart on it.
The point is, classifications are arbitrary. Scientists can call planets “spherical bodies that orbit a star and clear their orbits of other bodies” or they can redefine planets to mean “big things that orbit other big things” or go even further and define the word as “all things in the sky that are not clouds, planes, birds, or bugs.” But the only useful definition is the one that helps scientists do their jobs. It should not be influenced by people who like to complain about change, or who think that somehow scientists will hurt the feelings of an icy body forty astronomical units from the sun, even if it does have a cute big ol' heart on it.