Every Planet

Explore

Make a world.

Generate a world and read the physics behind it. The same seed gives the same world, picture and text as the iPhone app. Keep the ones you love.

Learn

Short recall questions.

Recall questions help the facts about each world stick. Layouts for phone, tablet and desktop. English and metric units only, no music.

Limits

Generated worlds, real relationships.

The generated planets are fictional. Their dossiers apply relationships such as Kepler’s third law to invented parameters, so the figures describe a consistent model, not observations. Progress lives in the browser, with an optional encrypted cloud backup opened by 24 words.