Planet
A World or Planet is an astronomical body located in the void, usually orbiting a star.
- The IISS also uses these astrographic terms near interchangeably.
Library Data Referral Tree
Please refer to the following AAB Library Data for more information:
- Charted Space Observation
Description (Specifications)
The term world refers to the various bodies that are contained in a stellar system; it encompasses planets, satellites, and asteroid belts. For example, the single most important world in a system may not be a planet; it could be a satellite of a gas giant, or it could be a planetoid within an asteroid belt. [1]
Planets possess a vast variety of identifying characteristics and can be categorized in many different ways. Some of the most common ways include: size, composition, exotic, and special natures.
Basic Planetary Types (Composition)
- Borean World (Ice Ball)
- Jovian World (Gas Ball)
- Terrestrial World (Rock or Iron Ball)
| Type | Nickname | Composition | Remarks |
|---|---|---|---|
| Terrestrial World: Silicate world | Ice Ball | Icy or rocky world. Ice or light silicate rock. | Density of 1.3 to 3.0 gm/cc^3, Borean World. |
| Terrestrial World: Low Iron world | Rock Ball | Rocky world. Heavy silicate rock, light metals. | Density of 3.1 to 4.5 gm/cc^3 |
| Terrestrial World: Medium Iron world | Rock Ball | Rocky world. Moderate mixing of iron and denser metals with silicate rock and lighter metals. | Density of 4.6 to 6.0 gm/cc^3. Terra is a Medium Iron world. |
| Terrestrial World: High Iron world | Iron Ball | Metal world. Mostly iron and denser metals with a few silicate rocks. | Density of 6.1 to 7.0 gm/cc^3 |
| Terrestrial World: Metallic world | Iron Ball | Metal world. Entirely iron and other dense metals. | Density over 7.1 gm/cc^3 |
| Jovian World | Gas Ball | Mostly gases & some solids. | Typically Gas Giants. Technically means huge world. Satellites of gas giants are known to have moons that can be habitable to conventional life. Jupiter is a gas giant. |
Basic Planetary Types (Size)
| Type | Code | Size | Atm | Hyd | Pop | Gov | Law | Remarks |
|---|---|---|---|---|---|---|---|---|
| Tiny World | None | 0RD | -- | -- | -- | -- | -- | (Dwarf World, Planetesimal, Planetoid, etc.) |
| Small World | None | S12 | -- | -- | -- | -- | -- | (Planetoid, Protoplanet, etc.) |
| Meso World | None | 345 | -- | -- | -- | -- | -- | (Mesoplanet) |
| Macro World | None | 678 | -- | -- | -- | -- | -- | Roughly Earth-sized. |
| Big World | None | 9AB+ | -- | -- | -- | -- | -- | A Super-Earth... |
| Gas Giant | SGG | SGG | -- | -- | -- | -- | -- | Small (SGG) gas giant. |
| Gas Giant | LGG | LGG | -- | -- | -- | -- | -- | Large (LGG) gas giant. |
- Please see AAB article Planetary Size for more information.
Exotic Planetary Types
These are Strange Worlds:
- Double World (Double Planet)
- Rosette World
- Doughnut World (Toroid World)
- Ellipsoid World
- Mobile World
- Ring Moon
- Ring World
- Rogue World
- Sphere World
- Tent World
| Type | Code | Size | Atm | Hyd | Pop | Gov | Law | Remarks |
|---|---|---|---|---|---|---|---|---|
| Double World | None | -- | -- | -- | -- | -- | -- | Double-planet mainworld. |
| Doughnut World | None | -- | -- | -- | -- | -- | -- | Toroidal world. A world with a hole in the center... |
| Ellipsoid World | None | -- | -- | -- | -- | -- | -- | Egg-shaped world. |
| Mobile World | None | -- | -- | -- | -- | -- | -- | Mobile world, whether natural or artificial, with added engines. Planetoid starships exist at TL-15. |
| Ring World | None | -- | -- | -- | -- | -- | -- | Artificial ring world. Megastructure. |
| Rogue World | None | -- | -- | -- | -- | -- | -- | Extrasystemic world. Thought to be very rare. |
| Sphere World | None | -- | -- | -- | -- | -- | -- | Artificial planetoid. |
| Tent World | 0-2 | -- | -- | -- | -- | -- | -- | A tented & paraterraformed world. Artificially constructed using Paraterraforming. |
Special Planetary Types
| Type | Code | Size | Atm | Hyd | Pop | Gov | Law | Remarks |
|---|---|---|---|---|---|---|---|---|
| Locked World | Lk | -- | -- | -- | -- | -- | -- | Locked close satellite. Gravitational relationship. |
| Main World | Mw | -- | -- | -- | -- | -- | -- | Socioeconomic center of a system. |
| Satellite World | Sa | -- | -- | -- | -- | -- | -- | Satellite or moon. Gravitational relationship. |
| Twilight Zone World | Tz | -- | -- | -- | -- | -- | -- | Twilight Zone. Orbit 0-1. Gravitational relationship. |
History & Background (Dossier)
Scientist argue about a variety of celestial objects and are constantly defining and redefining what is and isn't a planet:
- Planetary-Mass Object (PMO)
- Planemo
- Planetary body
- Dwarf planet
- Protoplanet
- Small Solar System Body (SSSB) [Minor planet]
The Solomani are particularly contentious in this area and the IAU (International Astronomical Union) definition of planet has fluctuated many times over the millennia.
Physical Planetology
This planetary grouping organizes by physical characteristics:
- Asteroid Belt World
- Big World
- Cold World
- Desert World
- Fluid World
- Frozen World
- Garden World AKA Terran Prime World
- Hell World
- Hospitable World
- Hot World
- Ice World
- Inferno World
- Inner World
- Inhospitable World
- Locked World
- Meso World
- Ocean World
- Outer World
- Panthallasic World
- Planetoid Belt World
- Rad World
- Small World
- Storm World
- Temperate World
- Tiny World
- Tropical World
- Tundra World
- Twilight Zone World
- Vacuum World
- Water World
- Worldlet
Socioeconomic Planetology
This planetary grouping organizes by socioeconomic characteristics:
- Agricultural World Series (Foodstuffs)
- Colony World Series (Subjugation)
- Industrial World Series (Manufacturing)
- Population World Series (Sophonts)
- Socioeconomic World Series (Wealth)
- Technology World Series (Tech)
- Low Tech World
- Average Tech World
- High Tech World
Biological Planetology
This planetary grouping organizes by bioplanetological (life-bearing) characteristics:
- Barren World
- Die Back World
- Garden World
- Home World
- Hospitable World
- Inhospitable World
- Reserve World
Bioplanetological Sciences
| Science | Actor Scientist |
Remarks |
|---|---|---|
| Exobiology | Exobiologist | The study of creatures, pre-sophonts, or lower intelligent lifeforms.
|
| Sophontology | Sophontologist | The study of sophonts or intelligent lifeforms. Includes Proto-sophonts |
| Terraforming | Terraformer | A planetary engineering process which, over many years, converts a hostile world (Inhospitable World) into a livable one (Hospitable World). |
Planet vs. World
What are the technical differences between the terms planet and world? In common usage, they are used interchangeably, but how do IISS scouts use the terms?
| Term | Remarks |
|---|---|
| Planet | Denotes an astronomic and astrographic meaning and applies to all of the bodies in a system. |
| World | Denotes a socioeconomic and sophontilogical meaning and mostly applies to those bodies with sophont populations, usually main worlds or satellite worlds. |
References & Contributors (Sources)
This list of sources was used by the Traveller Wiki Editorial Team and individual contributors to compose this article. Copyrighted material is used under license from Far Future Enterprises or by permission of the author. The page history lists all of the contributions.
- Marc Miller. Worlds and Adventures (Game Designers Workshop, 1977), —.
- Marc Miller. Scouts (Game Designers Workshop, 1983), —.
- Marc Miller. T5 Core Rules (Far Future Enterprises, 2013), —.
- Martin Dougherty. A Guide to Star Systems (Mongoose Publishing, 2015), —.
- Beowolf's Libary Data Website dead link
- Author & Contributor: Lord (Marquis) and Master of Sophontology Maksim-Smelchak of the Ministry of Science
- ↑ Marc Miller. Worlds and Adventures (Game Designers Workshop, 1977), 6.