When the International Astronomical Union (IAU) reclassified Pluto from planet to dwarf planet in 2006, it did nothing to change the fact of the existence of Pluto. Its status, however, is an innocuous example of how science is not always an objective descriptor of reality, but an interpreter, loaded with the context of previous generations – how the Greek “planetai” and the post-Copernican “planets” were both labels to describe things that moved in the heavens, even if we realised those things weren’t actually that similar to each other on closer inspection over time.
The scientific process often involves tweaking taxonomies. Humanity saw distant objects above, and the taxonomy we built was simple: two entries, one labelled “planets”, the other “stars”. Over time we added extra things, like asteroids (rocky) and comets (icy), to cover new discoveries – and, then, even further research (and pictures like those returned by the Rosetta probe) meant that some of the things we thought made asteroids and comets very different were really only a reflection of our perspective. (And, for what it’s worth, at the same meeting in 2006 where the IAU created the new term “dwarf planet” for objects like Pluto and “planet” for, y’know, planets, it also voted to use “small Solar System body” for everything else. This too will pass, probably.)
Content from our partners
