Planetary Classification System

The planetary classification system was created centuries ago by an Earth scientist.

At the time, the current United Coalition of Worlds was very poorly organized and didn't recognize a standard classification system. This one was ultimately adopted, which is why it uses some naming conventions based off the Sol system.

The base classifications are largely about mass and composition, while the subtypes relate more to climate, habitability, and notable features.

It is standard for the UCW and is used by non-aligned worlds sometimes too.

## CLASSIFICATION

#### Types

##### P - Protoplanet

(Uninhabitable, still forming, hot, chaotic)

Terrestrial or Gas

##### M1 - Minor planets and dwarf planets

Rocky, icy, and sometimes volcanic bodies

Mercurian - bigger than the Moon up to around the size of Mercury

Lunarian - smaller than Mercury up to the size of the Moon

##### M2 - Moons

Rocky, icy, and sometimes volcanic bodies

Mercurian

Lunarian

Subterran - moon the size of Mercury up to about the size of Mars

Terran - super rare; moons Earth-sized or bigger

##### T - Terrestrial planets

Rocky composition

Subterran - .3-.5 the size of Earth

Terran - .5-2 times the size of Earth

Superterran - 2-10 times the size of Earth

##### G - Gas Giant planets

Gas composition

Neptunian - 10-50 Earth masses

Jovian - 50-5000 Earth masses

##### D - Dark World

Each Dark World is unique

They exist only in sub-singularity dimensional spheres.

They can be any other type of classification as well.

#### SUB-TYPES

(usually given to M, D, or T class planets. Planets can have more than one subtype. These are mostly about climate and civilization as defining features)

##### F - Frozen world

Humans can't survive the elements without special equipment. (Not necessarily ice - just cold. Mars would be sub-type F.)

##### H - Extreme heat, desert world

Could also be L but usually have very little or even no surface water

##### W - Ocean world with little or no land

Generally must be 85% or more water.

Subtype W + Subtype F is essentially an ice world.

##### I - Intelligent life native to the world or colonised it

There are further sub-categories based on what type of intelligence.

1. Type O - primitive

2. Type I - a developing species with low technology, currently mastering control of their planet and star system

3. Type II - exploring their solar system and beyond

4. Type III - high technological advancement beyond most space-faring species

5. Type IV - ultra advanced, highly dangerous

6. Type Z - remnants of a past civilization; an abandoned world

##### L - Life supporting/habitable

(has life on it in the form of plants and animals; no intelligent life. Humans may or may not need pressure suits to survive)

1. Plants and insects only

2. Plants and small animals

3. Mega flora and fauna

4. Bacterial/microscopic. No macroscopic life.

##### C - Cataclysmic

A world that used to be inhabited or inhabitable but some cataclysm has struck, rendering it uninhabitable

##### V - Volcanic

Vulcanism can appear on any other world but volcanic worlds are dominated by active vulcanism.

1. Cryovulcanism

2. Normal vulcanism

##### E - "Empty" world

No structures, no plants, no animals. Rocky, barren, little to no atmosphere.

##### R - Rogue planet

Also called 'nomads'.

Rogue planets are planets that were ejected from their solar system. They float freely through the galaxy and are generally both dark and cold. A few of these so-called 'nomads' have retained their atmospheres and heat through internal or unknown mechanisms.