Architect of Worlds

Architect of Worlds is the working title for a sourcebook, covering plausible star system and world design, intended for science-fiction gaming and literary work. The book will discuss the fundamentals of astronomy and planetary science, and provide tools for creative individuals to use in designing star maps, stars, planetary systems, and individual worlds for their own settings.

This project will serve to compile and publish draft material for the Architect of Worlds book. Readers are invited to enjoy and use this draft material, and to contact me with any comments or suggestions. Once the draft is completed, the material will be compiled and published as an e-book.

General Outline


Star Maps

  • The Science of Star Maps
    • Shape and structure of the galaxy
    • Geography of the local galactic region
    • Normal density and distribution of star systems
    • Stellar associations and open star clusters
    • Classifying stars
    • Unusual stars and stellar remnants
    • Objects other than star systems
  • Drawing Star Maps
    • Determining the preferred scale of a setting
    • Determining the frequency of interesting worlds
    • How to draw a random fictional star map
    • How to place real-world objects onto a fictional star map
  • Designing Star Systems
    • Step One: Stellar Multiplicity
    • Step Two: Arrange Stellar Components
    • Step Three: Star System Age
    • Step Four: Star System Metallicity
    • Step Five: Stellar Initial Masses
    • Step Six: Stellar Evolution
    • Step Seven: Stellar Orbital Periods
    • Step Eight: Stellar Classification
    • Download Current Draft: Designing Star Systems (PDF, 889 KB)

Planetary Systems

  • The Science of Planetary Formation
    • A (not very typical) planetary system: our own
    • The classical model for planetary formation
    • Breakdown of the classical model (“hot Jupiters” and “super-Earths”)
    • Planetary migration
    • Stable and unstable orbital resonances
    • The emerging model for planetary formation (the Grand Tack hypothesis and the Nice model)
  • Designing Planetary Systems
    • Determining the mass and structure of the protoplanetary disc
    • Determining the presence, number, and mass of gas giant planets
    • Determining the dynamic evolution and final placement of gas giant planets
    • Determining the presence, number, mass, and placement of small inner planets
    • Determining the presence, number, mass, and placement of small outer planets
    • Determining the presence and placement of asteroid and planetesimal belts
    • Determining the presence, number, mass, and placement of major moons for each planet

Planets and Moons

  • The Science of Worlds
    • A classification scheme for worlds
    • Description of each category in the scheme (including constraints on physical properties)
  • Designing Worlds
    • Determining composition of solid body
    • Determining density, mass, and surface gravity of solid body
    • Determining orbital parameters (orbital eccentricity and period)
    • Determining rotational parameters (rotation period and axial inclination) including special cases (tide-locking, rotational resonance)
    • Estimating strength of magnetic field
    • Determining blackbody surface temperature
    • Determining abundance and composition of available volatiles
    • Assigning world classification
    • Determining average surface temperature
    • Determining details of atmospheric composition
    • Determining overall geographic parameters (plate tectonics, volcanism, presence and extent of oceans, presence and extent of ice sheets)
    • Determining prevalence and complexity of native life


  • Charts and Tables
  • No-Frills Design Sequence
  • References
  • Glossary
  • Index

© 2016-2017 Jon F. Zeigler