How many worlds can the Adventurers explore with the star system?
Populate star systems with the primary star(s) and the main setting world.
Each class and size of star creates a spherical zone where liquid water can exist, known as the “life”, “habitable”, or “Goldilocks” zone.
Is the main world closer to the star than the habitable zone, within the habitable zone, or deeper into the system beyond the habitable zone.
Add additional moons, rings, clusters, gas giants, and asteroid belts as desired.
For example, roll up to 4d6 for the number of additional objects in your star system.
Place smaller rocky worlds in the inner system and asteroids and gas giants further out from the primary star(s).
Inner rocky worlds may have 1d6 - 2 moons or rings, or orbiting clusters of rocks, but not both.
Outer gas giant worlds may have up to 4d6 significant moons, and as many smaller rings or rocky chunks as desired.
Plot and label the primary star and planets from left to right across the page in order from inner to outer system.
Below each planet indicate that world's moons, clusters, or rings vertically in order from nearest to most distant from the parent world.
While there are a number of online “solar system generators” available, Guides can start with StarGen.
StarGen generates planetary systems with many useful details such as orbital distance from main star (for star system mapping), the times to orbit (each world's length of year or moon's local time) and time to rotate (that world's length of day.)
StarGen also generates Eccentricity of Orbit which can be used to generate the varying length of seasons (again, if needed).
Example: 82 Eridani
The long standing benchmark for 2D/3D star mapping for writers and gamers will produce maps of the star systems generated around the stars:
AstroSynthesis (nbos)
Calculate the positions of planets in the Solar System:
An Orbit Map of the Solar System (tabletopwhale)