For navigational purposes most stars are classified based on the Harvard classification scheme, instead of the more detailed Herzsprung-Russel diagram. However, the in-game classification differs from the realworld scientific classification.

Star classes:

  • O Blue Giant
  • N White Giant
  • A Green Sun
  • F White Sun
  • G Yellow Sun
  • K Orange Sun
  • M Red Sun


The main focus of your exploratory expeditions. Most planets orbit around stars, altough some do traverse the universe alone in the ether without a parent star. Such planets are called rogue planets and are rather rare. Planets can orbit a star around 9 different orbits in Prospector and so there can never be more than 9 planets orbiting around a star at any given time. Most stars have less than 7 companion planets and a few have none. Planets are most common around Red Suns and least common around Blue Giants.


Atmosphere determins how easy it is to scan a planet from space, whether you have use oxyen reserves on the surface to breathe, how dangerous the planet is and how likely it is to find life there. There are 4 types of atmospheres: normal atmosphere, exotic atmosphere, corrosive atmosphere and no atmosphere. The four types come in different densities: remnant, thin, normal, dense and very dense atmosphere. For obvious reasons a world without atmosphere has no atmospheric density.


You have to use oxygen reserves or risk suffocating on all worlds, except those with normal atmosphere. Normal atmosphere is considered to be an earthlike nitrogen-oxygen atmosphere, exotic atmosphere might represent an atmosphere based on methane and a corrosive atmosphere might be an atmosphere high in sulfur dioxide, nitrogen oxides and/or other gases that easily form acids and corrode metals. Corrosive atmospheres are the most dangerous kind by themselves, since your awayteam can be burned by the atmosphere and the hydrosphere of such planets usually consists of acids, meaning acid lakes and oceans will block your way on the surface and possibly harm you, if you try to pass through them. Lifeforms are the most common on normal and exotic atmosphere worlds, planets with corrosive atmosphere are less likely to have life and planets without atmosphere are commonly without any lifeforms and they never have vegetation.


Density is less important than type. The only obvious effect the atmospheric density has is making scans from space reveal less surface area, if the atmosphere is dense. Dense atmosphere is also tougher for a rookie pilot to land in. Planets with extreme atmospheric densities are also less likely to have life.


Collecting minerals will be one of your main incomes so knowing which planets are the richest will make your life easier. All planets have a random regenerating amount of resources that is modified by the suroundings of the planet. Rogue planets are the richest followed by planets that orbit Blue Giants and then planets orbiting White Giants. Planets around Red Suns have the least amount of minerals. Also, planets that are within a nebula have more resources than those that aren't. The exact amount of resources a planet has is generated when you first scan or land on the planet and while a map obtained from scanning can give you the general picture about how rich a particular planet is, the only way to know exactly how many mineral deposits a planets has is to land and collects all of them.

Probability of LifeformsEdit

Most planets in Prospector have life and the probability usually doesn't so much tell you how likely a planet will have basic lifeforms like bacteria or amoeba, but how crowded the surface will be with alien monsters. Only a few planets will have a lifeform probability of 0% and the vast majority of these planets will be without atmosphere as such planets with atmosphere will be very rare. A ~20% probability means that there's likely to be only vegetation on the surface and any possible aliens will be few in numbers. Percentages up to 50% mean that there is going to be at least a group of aliens present. Percentages closer to 100% will mean hordes of aliens, a 90% world will have an alien almost every three squares in every direction, talk about overpopulation.

What most determines the probability of lifeforms is the orbit the planet is in and its atmosphere. The percentages are the highest near the central orbits, especially on the 3rd orbit, and lowest on the extremes. Planets without atmosphere have significantly less life and are commonly lifeless, even near the central orbits. Since rogue planets are without atmosphere as the rule, they rarely have any life. Exotic and normal atmosphere planets have the highest percentages and corrosive planets have a bit smaller percentages.

Asteroid fields and Gas GiantsEdit

Gas GiantsEdit

You will occasionaly meet these behemoths when exploring star systems. They're giant planets made out of various gases, usally hydrogen and helium, and you'll recognise them as large O's on the system maps. When you scan them or try to land on them you'll be asked if you want to try to refuel your ships in the atmosphere of the gas giant. This is a potentially dangerous manouver for a novice pilot in a light ship since, if botched, the manouver will cost you a Hull Point, but it will still give you the 5-20 points of fuel you'd get with a sucessful try. Even with an experience pilot and a good ship the refueling manouver is only worth it if you're very low on fuel, since not only has it the potential to destroy a ship with only one HP, but also fuel is alot cheaper than repairs. In additon to a chance to refuel, scanning a gas giant can lead to interesting, but dangerous, encounters.

Asteroid fieldsEdit

Asteroids are rocks floating in space and while significantly larger than a human being, they're usually too small to land a ship on. Asteroid fields are collars of giant rocks, if you will, that circle the stars. They're marked as grey boxes on the system maps. Scanning an asteroid field is usually done to find interesting asteroids within the field and may result in finding an asteroid with high amounts of a mineral or large asteroids that can be used to land a ship on. Sometimes small planets are hidden inside asteroid fields and will be discovered by scanning the field. Trying to land in an asteroid field is only meaningful, if you have discovered an asteroid large enough to land on trough prior scans. Warning, spacepirates are known to use asteroid fields to evade sensors and ambush unprepared ships.