Planetary Size
Planetary Size: Worlds are classified according to their physical size.
- Only Mainworlds (worlds or planets) of interest are recorded.
- e.g. Gas Giants are simply classified as Small (SGG) or Large (LGG).
Please see the following AAB Library Data articles for more information:
- Observing Charted Space
- Universal World Profile (UWP)
- Starport (Sp)
- Planetary Size (S)
- Atmosphere (A)
- Hydrosphere {H)
- Population (P)
- Government (G)
- Law Level (L)
- Tech Level (TL)
- PBG Sequence
- P: Pop Multipliers
- B: Belts
- G: Gas Giants
- TZ: Travel Zone
- COG Sequence
- Other System Data
- Universal World Profile (UWP)
Description (Specifications)
Planetary density and size are two primary factors when determining a planet's gravity.
Planetary Size Data
The following table outlines the UWP codes for the size of a body:
Planetary Size Code Description Diameter (Km) Expected
GravityRemarks R Asteroidlet / Planetary Ring (...around a world)
Multiple < 1 Microgravity
(0.01 G or less)Planetary Ring (Tiny World) D Debris 1+ < 200 Microgravity
(0.01 G or less)Debris Field / (Tiny World) 0 Asteroid / Planetary Belt (...around a star)
Multiple < 200 Microgravity
(0.01 G or less)Planetoid Belt (Tiny World) S Very Small 200-799 Very Low Gravity
(400 km, 0.02g - 0.03g)Very Small World 1 Small 800-2399 Very Low Gravity
(1,600 km, 0.05g - 0.09g)Small World 2 Small (e.g. Luna) 2,400-3,999 Low Gravity
(3,200 km, 0.10g - 0.17g)Small World 3 Small (e.g. Mercury) 4,000-5,599 Low Gravity
(4,800 km, 0.24g - 0.34g)Small World 4 Medium (e.g. Mars) 5,600-7,199 Low Gravity
(6,400 km, 0.32g - 0.46g)Meso World 5 Medium 7,200-8,799 Standard Gravity
(8,000 km, 0.40g - 0.57g)Meso World 6 Medium 8,800-10,399 Standard Gravity
(9,600 km, 0.60g - 0.81g)Meso World 7 Large 10,400-11,999 Standard Gravity
(11,200 km, 0.70g - 0.94g)Macro World 8 Large (e.g. Venus / Terra) 12,000-13,599 Standard Gravity
(12,800 km, 0.80g - 1.08g)Macro World 9 Large 13,600-15,199 Standard Gravity
(14,400 km, 1.03g - 1.33g)Macro World A (10) Huge 15,200-16,799 Standard Gravity
(16,000 km, 1.14g - 1.48g)Big World B (11) Huge 16,800 - 18,399 High Gravity
(17,600 km, 1.49g - 1.89g)Big World C (12) Huge 18,400+ Very High Gravity
(17,600 km, 1.9g - 2.0g)Big World SGG Small Gas Giant (no futher codes) 40,000-120,000 Macrogravity
(2.01 G or higher)Gas Giant LGG Large Gas Giant (no further codes) 120,000-240,000+ Macrogravity
(2.01 G or higher)Gas Giant
- NOTE-1: Please note that the size code D ( Debris ) is non-standard. It is included to cover such cases as Comet Mid-Rift (Deneb 3234), which are less than 200Km, but not part of an asteroid belt, yet important enough to have mention.
- NOTE-2: Please note that gravity values are estimations based on a standard planetary density. Planets with less or more dense cores may have very different values from the suggested average.
History & Background (Dossier)
When the UWP was created, any number of planetological figures were considered for inclusion. Initial discussion led to 16 and 32-factor descriptive chains, but theose were too many, especially for a Universal Code. Eventually the UWP was pared down to just eight factors. Of those eight factors, one of the most disputed was Planetary Size.
Size included many, many factors including:
- Gravity
- Physical measurement parameters
- Planetary density
- Tectonics
- Vulcanism
- etc.
A very unhappy compromise was eventually settled upon even though it as serious shortcomings.
Basic UWP Stats
Physical Stats (...the entire sequence):
SAH Sequence (planetology):
- S: Planetary Size (Size)
- A: Atmosphere
- H: Hydrosphere
PGL Sequence (socioeconomics):
- P: Population
- G: Government
- L: Law level
TL (technology):
Image Repository
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References & Contributors (Sources)
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- Marc Miller. Referee's Manual (Game Designers Workshop, 1987), .
- MegaTraveller World Builder's Handbook
- TNE World Tamer's Handbook
- The Universal World Profile
- Marc Miller. T5 Core Rules (Far Future Enterprises, 2013), 409,413.