Terminology: Dwarf Planet vs. ProtoPlanet

[DaveC426913]

For a Grade 9 textbook:

"Many more objects exist in the solar system besides the eight major planets. These are smaller and include moons, comets, protoplanets, such as Pluto, and tiny grains of dust and ice."

Is this acceptably-worded or is it misleading?

My take is that the term "protoplanet" refers to planetesimals that are part of a young still-forming system and have the potential to grow into planets. "Dwarf planets" are pretty much all they're ever going to be.

 

[Nabeshin]

I agree. Protoplanet suggests they're still in the process of forming, which is certainly not the case.

 

[DaveC426913]

I'm hoping for an authoritative answer from someone who knows these things so I can defend it to the editor.

 

[mgb_phys]

The IAU discussion about pluto calls them dwarf planets.
I have only seen protoplanet in the context of a proto-planetary disk

 

[sardar]

I would say that the terminology used in this textbook is somewhat misleading. While it is true that there are many objects in the solar system besides the eight major planets, the term "protoplanet" is not commonly used to refer to objects such as Pluto.

In scientific literature, the term "protoplanet" is typically used to describe early-stage objects in the process of planet formation, rather than objects that have already formed and are considered to be dwarf planets.

It would be more accurate to say that Pluto is a dwarf planet, rather than a protoplanet. Additionally, it is important to note that the term "dwarf planet" was only officially defined by the International Astronomical Union in 2006, so it may not be included in older textbooks.

Overall, I would suggest using the term "dwarf planet" when referring to objects like Pluto, and reserving the term "protoplanet" for objects that are still in the process of forming.