Reevaluating the Sol System

[AlexanderHowl]

Using the formulas from GURPS Space, I have created a spreadsheet that allowed for quick classification and discovered much to my surprise that there are number of objects that are technically planet-sized according to the formulas of GURPS Space that are not technically planets. In total, there are 32 extra planet-sized objects in the Sol System, though they are either dwarf planets (1 Main Belt and 21 Kuiper Belt) or satellites of larger objects (2 Kuiper Belt, 4 Saturn, and 4 Uranus). I was wondering if anyone else had come to the same realization that there are a lot more planet-sized objects than first appearances would suggest? The extra planet-sized objects are listed below:

1. Pluto (Kuiper Belt): Tiny (Ice)
2. Eris (Kuiper Belt): Tiny (Ice)
3. Haumea (Kuiper Belt): Tiny (Ice)
4. Titania (Uranus): Tiny (Ice)
5. 2007 OR10 (Kuiper Belt): Tiny (Ice)
6. Rhea (Saturn): Tiny (Ice)
7. Oberon (Uranus): Tiny (Ice)
8. Iapetus (Saturn): Tiny (Ice)
9. Makemake (Kuiper Belt): Tiny (Ice)
10. Charon (Kuiper Belt): Tiny (Ice)
11. Umbriel (Uranus): Tiny (Ice)
12. Ariel (Uranus): Tiny (Ice)
13. Dione (Saturn): Tiny (Ice)
14. Quaoar (Kuiper Belt): Tiny (Ice)
15. Tethys (Saturn): Tiny (Ice)
16. Sedna (Kuiper Belt): Tiny (Ice)
17. Ceres (Main Belt): Tiny (Rock)
18. 2002 MS4 (Kuiper Belt): Tiny (Ice)
19. Orcus (Kuiper Belt): Tiny (Ice)
20. Salacia (Kuiper Belt): Tiny (Ice)
21. 2002 AW197 (Kuiper Belt): Tiny (Ice)
22. 2003 AZ84 (Kuiper Belt): Tiny (Ice)
23. V774104 (Kuiper Belt): Tiny (Ice)
24. Varda (Kuiper Belt): Tiny (Ice)
25. 2015 RR245 (Kuiper Belt): Tiny (Ice)
26. Dysnomia (Kuiper Belt): Tiny (Ice)
27. 2004 GV9 (Kuiper Belt): Tiny (Ice)
28. 2005 RN43 (Kuiper Belt): Tiny (Ice)
29. 2002 UX25 (Kuiper Belt): Tiny (Ice)
30. 2007 JJ43 (Kuiper Belt): Tiny (Ice)
31. Varuna (Kuiper Belt): Tiny (Ice)
32. Ixion (Kuiper Belt): Tiny (Ice)

[Anthony]

GURPS Space (version 1 July 21 2006) predates the IAU changing the definition of planet (August 24 2006).

[AlexanderHowl]

I know, I am just saying that there are a number of objects that are planet sized by GURPS Space definitions that are not listed as such in GURPS Space (though many of the Kuiper Belt objects were undiscovered in 2006). Ceres is a Tiny (Rock) within the Main Belt and the Kuiper Belt possess 23 Tiny (Ice), though two of them are satellites of other objects. In addition, Saturn actually possesses 5 major moons rather than 1 major moon (when you include Titan) and Uranus possesses 4 major moons rather than no major moons.

[Phantasm]

I technically don't think Sedna qualifies as a Kuiper Belt Object, given that its orbit takes it well beyond the Belt, though it is a Trans-Neptunian Object.

But yes, I came to the same realization some time ago. I may have to readjust my number of "2d or 3d dwarf planets" per outer belt to 4d or more.

Of course, the need to stat them all out is entirely up to whoever is designing the system; I, personally, would probably just make one and use it as the "average" specimen.

[David Johnston2]

It has always been my assumption that there were too many useless big lumps of ice in the Kuiper Belt to be worth counting.

[RyanW]

Originally Posted by Phantasm

But yes, I came to the same realization some time ago. I may have to readjust my number of "2d or 3d dwarf planets" per outer belt to 4d or more.

You could do a (1d-1)d sort of roll. Though we are operating from a sample size of one, and we aren't even sure yet if we know of all the gas giants in our system.

[Agemegos]

Originally Posted by David Johnston2

It has always been my assumption that there were too many useless big lumps of ice in the Kuiper Belt to be worth counting.

Mine also.

[AlexanderHowl]

Well, they are useless to us now, but it is nice to know that they exist for the future. Even a small world like Ixion probably masses over 226.5 quadrillion metric tons. With at least ten percent the mass being something else than ice, that means that it possesses more usable material than the vast majority of the asteroids in the Main Belt. Even if everything that is not ice is similar in composition to S-Type asteroids, that translates to around 1.97 trillion metric tons of precious metals.

As for the number of dwarf planets, I use the RVM of an asteroid belt (with each increase in RVM representing a fourfold increase in asteroid belt mass). At 0, it has 1 dwarf planet, and increases the number of dwarf planets by fourfold for every +1. Since the Kuiper Belt possesses 20-200 times the mass of the Main Belt (averaging 110 times the mass), I give it an RSM of +3, meaning that it could have up to 64 dwarf planets.