About StarForge Play

How it works

StarForge teaches astronomy the way explorers actually learn the sky: from real data about real worlds, and by predicting what will happen before you look.

• Solar System Explorer — an orbit map of the Sun and eight planets. Tap any world to open its Discovery Codex — real diameter, gravity, day and year length, moons, distance and temperature — then take a short mission challenge about it.
• Orbit & Phase Lab — predict the Moon's phase from where it sits in its orbit before you see the answer, and predict your weight on other worlds. Every reveal explains why — including why phases come from the Sun–Moon–Earth angle, not Earth's shadow.
• Concept kits — 16 short question rounds, from our solar system out to galaxies and the Big Bang.

Our privacy promise

StarForge Play is free, works offline, and collects nothing. No accounts, no ads, no tracking, and no data ever leaves your device — your progress, level, and streak are saved only in this browser.

Mistakes are part of it

You never lose anything for a wrong try. In the Orbit & Phase Lab, making a prediction — even a wrong one — is exactly what helps the idea stick. Wrong answers get a gentle explanation, and hints teach you how to reason, not just the answer.