Planet

A planet is a small object containing a variety of compounds formed from the remains of a star. Making up an estimated 20% of the planet population in our local Universe, planets with organics and reactive liquids are likely to host a civilization. Our local planet Earth is the only known example of such a planet. Planets are also known to have a variety of moons orbiting them. Planets outside of our local system have been named exoplanets.

Gas Planet
These are the most common type of planet, with thick atmospheres. They collected hydrogen and helium over time, and are similar to stars. We have 4 such planets in our local system. Most of them are larger than either of the other two types.

Ocean Planet
A planet composed of 100% water. Sometimes also extended to include ice planets. If an ocean planet becomes hot enough, it may begin to resemble a small gas planet with a thick steam atmosphere. They have intermediate size between terrestrial and gaseous.

Terrestrial Planet
An umbrella term for all planets aside from the previous classes. These have many different subtypes such as terran planets and iron planets.