About the project

A city-scale model of the solar system you can walk.

Most solar-system models are inaccurate: they shrink the planets and keep them close together. The real distances are enormous and they don't fit conveniently on a poster. SolarSystem.city came from a question — what would it look like at actual scale? Pick a real object in your city to stand in for the sun, and every planet's size and orbit falls out from that scale. Ultimately it's an excuse to get people outside, hanging out and touching grass.

The "Sun" object

Every mission is anchored to a single real-world landmark that stands in for the sun. In New York, for example, one "sun" is The Sphere (the Koenig Sphere) in Liberty Park. Its real diameter sets the scale for the rest of the mission. Once the sun's size is fixed, the size of every planet and the distance to every orbit are deterministic.

How the scale works

Math! If the sun is rendered at a few feet across instead of its true diameter, that ratio is the scale factor:

scale_factor = real_sun_diameter / sun_object_diameter

A planet's rendered size is its real diameter divided by the scale factor; its distance from the sun object is its real orbital distance divided by the scale factor.

One deck, every city

The cards carry no city information at all. A card is two things: a QR entry point and a printed AR image target the app uses to reference the planet scale. Which city you're in is resolved at runtime from your GPS location, so the same physical deck produces a different true-scale walk in every supported city.

No accounts, no tracking

There are intentionally no logins and no personal data exchanged. Your progress through a mission lives only in your browser's local storage. Clear it and you start fresh.