Delta Quadrant: Horizons uses its own planet classification, mostly inspired from movies and games. There are 13 planet types grouped in 7 planet classes.

Planets can vary in size, and in Delta Quadrant: Horizons they are grouped into 5 sizes. These are tiny, small, medium, large and huge. The smallest planets tend to have Low gravity, while the biggest ones usually have Heavy gravity. Planets with Low or Heavy gravity have lower production output (-25%) than planets with average gravity.

Mineral abundance on a planet can vary, from Ultra Poor to Ultra Rich. The lower class planets tend to be the richest in minerals, while higher class planets tend to be poorer in minerals. Mineral abundance effects the amount of base production of a worker, see the table below.

MINERAL ABUNDANCE

Mineral Abundance	Effect on base worker production
Ultra Rich	8
Rich	5
Average	3
Poor	2
Ultra Poor	1

	Gas Giant Planets of this class are usually found in a stars outer zone or 'cold zone'. They have high core temperatures causing them to radiate heat. Low stellar radiation and heavy planet gravity make them unhabitable. 'Gas Mining Complex' technology required to colonize these planets. The harsh surface conditions on these planets increases maintenance costs. Farming is not possible on these planets.	0	0.25%		+50%	20	2
	Asteroid Planetary bodies of this class can be found in any of a star's zones. They have no atmospheres, and their surfaces are barren and cratered. 'Asteroid Mining Complex' technology required to colonize these planets. Constant meteor showers and collisions increases maintenance costs. Farming is not possible on these planets.	1	0.25%		+50%	15	3
	Crystalline (Toxic) These planets have surfaces that are still crystallising. Volcanic activity fills the atmosphere with toxic gases and dust, causing the planet to be unsuitable for life. The toxic environment on these planets increases maintenance costs. Farming is not possible on these planets.	1	0.25%		+25%	1	3
	Crystalline (Radiated) These planets are still cooling and have a thin atmosphere. Reactions in the core, and rays from its star cause the planet to be very radioactive, and as such unsuitable for supporting life. High levels of radiation on these planets increases maintenance costs. Farming is not possible on these planets.	1	0.25%		+50%	1	3
	Crystalline (Barren) Planets of this class have no atmosphere, and volcanic activity causes its surface to be barren and cratered. They are unsuitable for supporting life. Farming is not possible on these planets.	1	0.25%			1	3
	Adaptable (Desert) Planets of this class have hot, dry climates with very little water. Some simple life forms can survive on these worlds, but usually only in the more sheltered regions. Violent sandstorms on these planets increases maintenance costs.	2	0.5%	0	+25%	1	3
	Adaptable (Tundra) These planets are largely frozen wastelands. Their surfaces are severe, but volcanic vents below the ice provide ideal conditions for simple life forms to flourish.	2	0.5%	0		1	3
	Adaptable (Arid) First signs of biological life are usually found on planets of this class. They have thin atmospheres and small amounts of water are present.	2	0.5%	0		1	3
	Pelagic (Swamp) Planets of this class have atmospheres suitable for life. Water and life-forms are typically abundant. Although, it is a very suitable planet for biological races, the climate is still severe.	3	0.75%	1		1	3
	Pelagic (Ocean) Water is abundant on planets of this class, and aquatic life can be found throughout. The large amounts of water in the atmosphere cause them to have frequent and violent storms. Violent storms and high humidity on these planets increases maintenance costs.	3	0.75%	1	+25%	1	3
	Terrestrial Planets of this class are found in a star's 'habitable zone'. They have atmospheres, water and life-forms are typically abundant.	4	1%	2		5	2
	Alpha-Gaea Planets of this class are considered 'paradise' by biological races. They are mainly the same as Terrestrial class planets but with a stable climate.	5	2%	3		10	1
	Alpha-Gaea (Guardian Planet) A Super Alpha-Gaea planet, the biggest and richest one. This planet was developed by an ancient race and is protected by Guardian machines.	10	5%	10		20	0

The colonization limit is the cap of colonization for your empire. You can increase the limit by researching the governance technologies, starting with X-Psychology. Also, every 500 turns the colonization cap will increase by 10. The colonization limit is determined by points a colonized planet uses. You can colonize and go above the limit, but in this case the overall productivity of your empire will decrease.


Some planets may contain ancient artefacts. These artefacts are remnants of an unknown civilisation or race. Despite their origins being unknown, they can be very useful to any colony built on the planets where they are found. Below is a list of artefacts and the benefits they provide.

Artefact
Bio-gel A mysterious biological gel, of an unknown origin. It is a very good fertiliser for crops.	Increases food output of each assigned farmer by 300 units.
Assembly Module An automated assembling unit. It looks as though it was designed for a much larger structure of some kind.	Increases production output of each assigned worker by 500 units. Decreases pollution by 10000 units.
Sentient Library A great library of untold secrets. It feels alive with history and knowledge.	Increases research output of each assigned scientist by 150 units.
Bio-forming Unnaturally high amounts of biomass are present on this planet, showing some past attempt at developing its ecosystem. It is a great advantage to farming.	Increases food output on a colony by 3000 units, regardless of assigned farmers. Increases maximum population limit on a colony by 5 M.
Cyber Mine An automated mine created from billions of nano-machines. Its creator is unknown.	Increases production output on a colony by 10000 units, regardless of assigned workers. Decreases pollution by 5000 units.
Abandoned Laboratory A laboratory that has long been abandoned. It is still in good condition, and contains many advanced tools and facilities.	Increases research output on a colony by 5000 units, regardless of assigned scientists.
Aphrodisiac Pollen A mysterious pollen that fills the atmosphere. It increases the fertility of all who breathe it.	Increases population growth on a colony by 5 %. Increases food output on a colony by 1000 units, regardless of assigned farmers. Increases maximum population limit on a colony by 15 M.
Y-Units Y-shaped conglomerates of nano-machines, their origin is unknown. They seem impelled to repair any forms of metallic corrosion they come into contact with, often repairing buildings.	Decreases maintenance costs on a colony by 100 %. Increases production output on a colony by 5000 units, regardless of assigned workers. Decreases pollution by 3000 units. Increases maximum population limit on a colony by 10 M.
Traders' Vault A huge vault full of countless treasures. It must have been built by a huge trade organisation.	Increases colony income by 1500 %.
Ancient Metropolis A vast city of ancient, but well preserved buildings. It shows the great skills of its architects and designers, whoever they may be.	Increases maximum population limit on a colony by 30 M.