The rocky planets or the planets similar to Earth are the best targets for terraforming processes. There are many types of known or hypothetical planets to be taken into consideration. The following is a page containing the main categories of planets and some common terraforming pathways.
A rocky planet is defined as a planet that contains mainly materials that on average Earth temperatures will be solid, forming a crust. The surface can be covered partially or totally with water or other fluids, but the solid soil can be reached. There are 3 types of rocky planets, based on size: Super Earths, Earth - Like Planets and Small Planets.
A more forced definition of a rocky planet is: a planet that does not have a large gas layer and its solid surface can be touched or measured. This definition includes planets that might exist far away from their parent stars (and that might be composed of water ice and solidified gasses) from Gas Giants.
According to IAU, the definition of a planet is  the following: a celestial body that orbits a star, has a round/ellipsoid shape and has cleared its neighbourhood. In addition, a Rough planet is a celestial body that has a round-ellipsoid shape and is free-floating in interstellar space. The IAU definition of a planet means that Pluto, Ceres, Eris or Sedna are not planets, in fact they have been listed as dwarf planets.
The IAU definition was contested by many people, resulting even in street demonstrations from people who support Pluto of a planet. The point is that, this definition has some problems. The following theoretical examples will show what confusion this theory will create to future settlers in other solar systems:
- Suppose a solar system has instead of our Neptune a planet that is 4 times the mass of Jupiter. That planet could support on stable orbits much larger Kuiper Belt Objects (even to the size of Uranus), on 1/2 and 2/3 orbit resonances (like Neptune and Pluto are).
- A Super-Jupiter can maintain as Trojans asteroids and even planets, on safe orbits.
- It is possible for a rocky planet to be a quasi-satellite of a gas giant.
- Around big stars, smaller stars or brown dwarfs can have gravitational influences similar to the outer planets in the Solar System. In this scenario, we can see an asteroid belt that might contain planet-sized objects.
- There could exist planet-sized objects moving chaotic, or passing for a limited time through a solar system.
For future terraformers, it is not so important how to classify a body. The most important thing is how we can terraform it. So, the theoretical models listed below might not all be actually planets. The list includes celestial bodies that are large enough to have a spheroid/ellipsoid shape (so, larger then Asteroids), but that don't hold or are unable to hold giant atmospheres (so, smaller then Gas Giants). The models described are planets (or dwarf planets), but many moons might behave similar and can be terraformed by using similar methods.
The models are listed based on the Solar Constant - Ks (the amount of heat received from the parent star).
Hot models Edit
See also Inner Planet (Ks>4)
- Hot planets (Ks>400) - planets located so close to their star that surface temperature exceeds 1000 C
- Vulcanoid Type Planet (40>Ks>400) - from the theoretical planet Vulcan, are closer to their star then Mercury and so they receive far more heat
- Hermian Type Planet (4>Ks>40) - from the adjective hermian that defines something related to Mercury
Average models Edit
See also Earth - like planet (0.4<Ks<4)
- Habitable Zone Planet (0.4<Ks<4) - a planet that is within the Habitable Zone, where temperatures suitable for life would naturally occur
Cold models Edit
See also Outer Planet (Ks<0.4)
- Galilean Type Planet (0.04<Ks<0.4) - from the large Galilean moons of Jupiter
- Titanian Type Planet (0.004<Ks<0.04) - from the moon Titan of Saturn
- Kuiper Type Planet (0.0004<Ks<0.004) - includes Neptune, the outer limit where plat life can exist
- Sednoid Type Planet (0.00004Ks<0.0004) - from dwarf planet Sedna, which orbits within this area
- Oort Type Planet (Ks<0.00004) - planets too far from their stars or free-floating planets.
Special models Edit
- Artificial Planet
- Carbon Planet
- Desert planet
- Dry cold planets
- Earth - like planet
- Elliptical orbit
- Failed Earth
- Fireball Earth
- High gravity rocky planet
- Hyperbolic Planet
- Inner Planet
- Metal Planet
- Mountain Planet
- Nearly Tidal Locked Planet
- Oceanic Planet
- Outer Planet
- Plain Planet
- Retrograde Planet
- Reservation Planet
- Short Lived Earth
- Rogue planet
- Salt Ocean Planet
- Small Planet
- Snowball Earth
- Tidal Locked Planet
- Venus - Type Planet
- YZ Planet