Class A - Geo-Thermal

Age: 0-2 billion years

Diameter: 1,000 - 10,000 km.

Location: Ecosphere / Cold Zone

Surface: Partially molten

Atmosphere: Primarily hydrogen compounds

Evolution: Cools to become Class C

Lifeforms: None


Example: Gothos

Class B - Geo-Morteus

Age: 0-10 billion years

Diameter: 1,000 - 10,000 km.

Location: Hot Zone

Surface: Partially molten, high surface temperature

Atmosphere: Extremely tenuous, few chemically active gases

Evolution: -

Lifeforms: None


Example: Mercury

Class C - Geo-Inactive

Age: 2-10 billion years

Diameter: 1,000 - 10,000 km.

Location: Ecosphere / Cold Zone

Surface: Low surface temperature

Atmosphere: Frozen

Evolution: -

Lifeforms: None


Example: Pluto, Psi 2000

Class D - Asteroid/Moon

Age: 2-10 billion years

Diameter: 100 - 1,000 km.

Location: Hot Zone / Ecosphere / Cold Zone; found primarily in orbit of larger planets or in asteroid fields

Surface: Barren and cratered

Atmosphere: None or very tenuous

Evolution: -

Lifeforms: None


Example: Moon (Sol IIIa), Lunar V (Bajor VIIe)

Class E - Geo-Plastic

Age: 0-2 billion years

Diameter: 10,000 - 15,000 km.

Location: Ecosphere

Surface: Molten, high surface temperature

Atmosphere: Hydrogen compounds and reactive gases

Evolution: Cools to become Class F

Lifeforms: Carbon-cycle (Excalbian)


Example: Excalbia

Class F - Geo-Metallic

Age: 1-3 billion years

Diameter: 10,000 - 15,000 km.

Location: Ecosphere

Surface: Volcanic eruptions due to molten core

Atmosphere: Hydrogen compounds

Evolution: Cools to become Class G

Lifeforms: Silicon-based (Horta)


Example: Janus VI

Class G - Geo-Crystalline

Age: 3-4 billion years

Diameter: 10,000 - 15,000 km.

Location: Ecosphere

Surface: Still crystallizing

Atmosphere: Carbon dioxide, some toxic gases

Evolution: Cools to become Class K, L, M, N, O, or P

Lifeforms: Primitive single-celled organisms


Example: Delta-Vega

Class H - Desert

Age: 4-10 billions years

Diameter: 8,000 - 15,000 km.

Location: Hot Zone / Ecosphere / Cold Zone

Surface: Hot and arid, little or no surface water

Atmosphere: May contain heavy gases and metal vapors

Evolution: -

Lifeforms: Drought and radiation-resistant plants, animal life


Example: Rigel XII, Tau Cygna V, Ocampa, Nimbus III

Class I - Gas Supergiant

Age: 2-10 billion years

Diameter: 140,000 - 10 million km.

Location: Cold Zone

Surface: Tenuous, comprised of gaseous hydrogen and helium compunds; radiates heat

Atmosphere: Zones vary in temperature, pressure and composition; water vapor may be present

Evolution: -

Lifeforms: Unknown


Example: Q'tahL

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 helium compunds; radiates some heat

Atmosphere: Zones vary in temperature, pressure and composition

Evolution: -

Lifeforms: Hydrocarbon-based (Jovian)


Example: Jupiter, Saturn

Class K - Adaptable

Age: 4-10 billion years

Diameter: 5,000 - 10,000 km.

Location: Ecosphere

Surface: Barren, little of no surface water

Atmosphere: Thin, mostly carbon dioxide

Evolution: -

Lifeforms: Primitve single-celled organisms; adaptable for humanoid colonization through the use of pressure domes


Example: 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

Evolution: -

Lifeforms: Limited to plant life; suitable for humanoid colonization


Example: Indri VIII

Class M - Terrestrial

Age: 3-10 billion years

Diameter: 10,000 - 15,000 km.

Location: Ecosphere

Surface: Surface water abundant; if water or ice covers more than 80% of surface, planet is considered Class O or Class P

Atmosphere: Nitrogen, oxygen, trace elements

Evolution: -

Lifeforms: Extensive vegetation, animal life, humanoids


Example: Earth, Vulcan, Cardassia Prime

Class N - Reducing

Age: 3-10 billion years

Diameter: 10,000 - 15,000 km.

Location: Ecosphere

Surface: High surface temperature due to greenhouse effect; water exists only as vapor

Atmosphere: Extremely dense, carbon dioxide and sulfides

Evolution: -

Lifeforms: Unknown


Example: Venus

Class O - Pelagic

Age: 3-10 billion years

Diameter: 10,000 - 15,000 km.

Location: Ecosphere

Surface: Liquid water covers 80% or more of surface area

Atmosphere: Nitrogen, oxygen, trace elements

Evolution: -

Lifeforms: Aquatic vegetation, animal life, humanoids


Example: Pacifica, Argo

Class P - Glaciated

Age: 3-10 billion years

Diameter: 10,000 - 15,000 km.

Location: Ecosphere

Surface: Water ice covers 80% or more of surface area

Atmosphere: Nitrogen, oxygen, trace elements

Evolution: -

Lifeforms: Hardy vegetation, animal life, humanoids


Example: Andoria, Breen Homeworld, Exo III

Class Q - Variable

Age: 2-10 billion years

Diameter: 4,000 - 15,000 km.

Location: Hot Zone / Ecosphere / Cold Zone

Surface: Ranges from molten to water and/or carbon dioxide ice, due to eccentric orbit or variable output of star

Atmosphere: Ranges from tenuous to very dense

Evolution: -

Lifeforms: Unknown


Example: Genesis Planet, Meridian

Class R - Rogue

Age: 2-10 billion years

Diameter: 4,000 - 15,000 km.

Location: Interstellar space, cometary halos

Surface: May be temperate due to geothermal venting

Atmosphere: Primarily volcanic outgassing

Evolution: -

Lifeforms: Non-photosynthetic plants, animal life


Example: Dakala, The Founders' Homeworld

Class S/T - Near Star

Age: 2-10 billion years

Diameter: 10-50 million km. (Class-S) <br> 50-120 million km. (Class-T)

Location: Cold Zone

Surface: Tenuous, composed of gaseous hydrogen and helium compounds; radiates considerable heat

Atmosphere: Zones vary in temperature, pressure and composition; water vapor may be present

Evolution: -

Lifeforms: Unknown


Example:  

Class Y - Demon

Age: 2-10 billion years

Diameter: 10,000 - 50,000 km.

Location: Hot Zone / Ecosphere / Cold Zone

Surface: Temperature can exceed 500K

Atmosphere: Turbulent, saturated with toxic chemicals and thermionic radiation

Evolution: -

Lifeforms: Mimetic (Delta Quadrant)


Example: Tholia