Pluto is finally getting its day in the sun, after being stripped of planetary status by astronomers two years ago.
From now on all similar distant bodies in the solar system will be called "plutoids." - Pluto Gets Respect: Dwarf Planets to Be Called 'Plutoids'

På et vis er hele greia ganske komisk, men viser jo litt hvor problematisk og kontroversielt det kan være å lage definisjoner. Spesielt kanskje når noe blir "demotert". Planet, dverg-planet, plutoid...

Og da kom det plutselig en ny klasse og en ny definisjon. Forenklet sier den sånn ca "dverg-planet utenfor Neptuns bane." For å være sikker på at Pluto fremdeles er en plutoid den tiden den er innenfor Neptuns bane brukes "semimajor axis" i definisjonen. For så vidt logisk.

Plutoids are celestial bodies in orbit around the Sun at a semimajor axis greater than that of Neptune that have sufficient mass for their self-gravity to overcome rigid body forces so that they assume a hydrostatic equilibrium (near-spherical) shape, and that have not cleared the neighbourhood around their orbit. Satellites of plutoids are not plutoids themselves, even if they are massive enough that their shape is dictated by self-gravity. The two known and named plutoids are Pluto and Eris. It is expected that more plutoids will be named as science progresses and new discoveries are made. - IAU0804: Plutoid chosen as name for Solar System objects like Pluto

Stakkar Ceres som står igjen mutters alene.