Planet Classification

The Senate has instituted a system for "grading" planets and moons based on type and habitability for ease of stellar navigation. These classes are listed below.

Class I - Uninhabitable
Class I worlds usually lack an atmosphere, or possess only the barest wisps of one. Usually, this is a class assigned to small, rocky moons (like Earth's, or like Pluto's companion, Charon) or to the minor planetoids which form in asteroid belts, outer belts (Kuiper belts) or solar limit fields (Oort clouds). Although Class I worlds make excellent weapons test sites, they make laughably poor colony locations and are therefore considered all but worthless.

Class II - High-Level Hazards
These are planets which can be similar to Venus, in which runaway greenhouse emissions have created pressure-cooker worlds. Mercury also falls into this category, as it is considered a high-level hazard planet due to its proximity to its host star and lack of atmosphere to protect it from ionization. These worlds are often ignored unless they possess valuable resources for colonization on other planets in the system, or rare minerals and metals such as iskindite or larcorium. They are habitable, but barely. Many other extreme hazards can contribute, but they are usually limited to poisonous atmospheres, lethal weather systems, location in the system (i.e. Mercury or Venus) and temperature.

Class III - Medium-Level Hazards
Medium-level hazards often consist of one or two dangerous weather types (such as acidic rain or noxious winds) but can also be expanded to include unusually high/low temperature fluctuations. A planet like Arctus, which waffles between blazing summers and freezing winters across the globe due to an extremely elliptical orbit, can fall into this category. Class III planets are among the most common worlds in the Galaxy, and are often colonized with small- to mid-size settlements. They can be farmed easily in the case of a world like Arctus, but most only possess minimal plant or animal life.

Class IV - Low-Level Hazards
Class IV planets are not as common as a Class III, but are widely prized when found. They possess almost no dangers (apart from the possibility of atmospheric composition differences) and usually sustain a variety of plant and animal life. They are almost always colonized as soon as they are discovered, and can support a variety of mid-sized setlements with ease. Weather patterns usually fluctuate between temperate and severe, which is the only real hazard. Some Class IV planets are also only considered such due to geological activity. Normark is one example of a Class IV world.

Class V - Garden World
Planets like Chindrus or Earth are considered Class V worlds. These are almost completely covered with lush plant life and teeming with an assortment of fauna. Class V "Garden Worlds" are commonly the source of sentient life because of the globally stable weather, tolerable temperatures, and often the presence of liquid, non-acidic chemicals (such as, but not restricted to, water). Large, sprawling cities are usually established, as are many smaller towns or villages. Class V worlds can support large populations with ease as well, and any Garden Worlds not already the site of active civilizations are quickly snatched up by competing races.

Class T - Terraformed Worlds
Once the Elorskra joined the Senate approximately 40 million years ago, they brought with them advanced technologies which were capable of stabilizing atmospheres and even altering weather patterns. This gave rise to "Terraforming", which enabled races to raise or lower the class of a planet. Through careful manipulation of the chemicals present in a world, as well as an alteration of the valence electrons within each element, even lifeless worlds like the Moon can be given robust, healthy atmospheres. Terraforming, however, requires a massive and constant expenditure of energy. Fusion plants, at minimum, are a requirement. Furthermore, if any of the terraforming spires are damaged, it can result in a drop in air quality, atmospheric density, etc. and, if left unchecked, an entire world's population of plant, animal and sentient life can be killed off in a few months. Terraformed planets are denoted on Galactic charts by stating their current class with a capital "T" after it (for example, in the case of Mars, it would be listed as "Mars, Class IV-T" if it had been raised to a class IV.)

Class Z - Anu'bai Contaminated Worlds
Not normally seen, as the Senate deals with these worlds quickly, the Class Z worlds arose after the appearance of the Anu'bai some 5,000 years ago. These worlds are unhealthy, and it shows from orbit. Thick, brownish-green growths choke the world, and the atmosphere follows suit, usually glowing a toxic greenish-brown. The only cure for these worlds is sterilization, and the Senate is swift to move in and burn these worlds to until their surfaces are nothing but charred embers. Thus far, this has been the only proven way to effectively end an Anu'bai threat.

Class X - Progenitor-Altered Worlds
When Progenitors absorb worlds, they alter them irrevocably. Every cell of organic matter is dissolved and replaced with duplicates of synthetic life. These worlds gleam like diamonds or metal fragments from space, and closer inspection reveals forests of synthetic trees. Often times, these were once Class III or IV worlds that fell to the Progenitors, and now all life has been replaced by this mechanical mockery. Although beautiful to look at, they are often outposts or hiding places of Progenitors. "Planet Crackers", or antimatter bombs, are usually used to destroy these worlds before they can become a threat.

Class A - Ringed Worlds
Class A Jovians are Saturn-type worlds, often with spectacular rings and many moons. They usually form further form the star than other planets, where it is cooler and the dust and ice in their rings will not evaporate. Saturn is the obvious example for a Class A planet.

Class B - Ringless Worlds
These are enormous planets that lack rings, but still have many moons around them. Jupiter is an excellent example (although it still has faint rings, which qualifies it as a low-grade Class A). They tend to form closer to the star than a Class A.

Class C - Hot Giants
Class C worlds are gas giants which form very close to their star, often heating up and evaporating quickly. They are usually close to the size of Neptune or Uranus, but may or may not be formed from similar compositions. They transit quickly around their star in most cases, due to their close proximity, but slow Class C's have been discovered. Due to their closeness to the parent star, they do not develop rings.

Class D - Ice Giants
A Class D world is the opposite of a Class C. They form far away from their stars, cooling considerably into what humans call "ice giants". This is the official class of Neptune and Uranus. They often do not possess as many moons as A or B class planets, although a few examples with 30+ moons have been discovered. Some Class D planets have rings, but it is not a defining requirement.

Class S - Binaries
This is a VERY rare type of planet. Early in its formation, a gas giant can split apart if tidal shearing (usually as a result of multiple suns) is strong enough. The gases then recombine into two individual worlds orbiting a shared center of gravity - a binary jovian planet. The exact mechanism which forms these worlds is unknown, as some shorn planets recombine into a single world while others form Class S binaries. Moons generally orbit the shared center of gravity as well, swinging around both gas giants. Due to the tidal forces of the two worlds, however, most moons end up falling into the planets themselves and being crushed. The few outer worlds that survive are almost never habitable as a result of the extreme tidal forces.

Class L
"Lifeboat Planets" are those which have been evicted from their original systems, usually early in their history. These wandering worlds drift between the stars, sometimes collecting small moons (or other Class L worlds) and forming miniature systems. Due to the lack of a sun, however, no habitable Class L worlds ahve ever been found. Class Ls are also divided into two subgroups: Class L1 and Class L2. A Class L1 world is a terrestrial Lifeboat planet (like the Heil planets, Logic or Shadow) while Class L2 are non-Terrestrial Lifeboat planets.