Star Charts · Chapter 3 · Planets
3.3 Planetary Classes J–L (Gas Giant, Adaptable, Marginal)
Reference data for planetary classes J, K and L, listing age, diameter, location, surface, atmosphere, life-forms and examples for each.
Class J Gas Giant, a banded ringed gas world resembling Jupiter.
Class K Adaptable planet, a barren reddish-tan world resembling Mars.
Class L Marginal planet, a rocky greenish-grey world.
Class J — Gas Giant
- Age: 2-10 billion years
- Diameter: 50,000-140,000 km
- Location: Cold Zone
- Surface: Tenuous, comprised of gaseous hydrogen and hydrogen compounds; radiates some heat
- Atmosphere: Zones vary in temperature, pressure and composition
- Life-forms: Hydrocarbon-based (Jovian)
- Examples: Jupiter, Saturn
Class K — Adaptable
- Age: 4-10 billion years
- Diameter: 5,000-10,000 km
- Location: Ecosphere
- Surface: Barren, little or no surface water
- Atmosphere: Thin, mostly carbon dioxide
- Life-forms: Primitive single-celled organisms; adaptable for humanoid colonization through the use of pressure domes
- Examples: Mars, Mudd
Class L — Marginal
- Age: 4-10 billion years
- Diameter: 10,000-15,000 km
- Location: Ecosphere
- Surface: Rocky and barren, little surface water
- Atmosphere: Oxygen/argon, high concentration of carbon dioxide
- Life-forms: Limited to plant life; suitable for humanoid colonization
- Example: Indri VIII