Star Field
Pick constellations and their brightest stars out of a real sky, computed for a latitude, a date and a light-polluted limiting magnitude.
5
levels3–12 min
a run, player-paced3
samplesNo timer
player-paced, always
Star Field
Pick constellations and their brightest stars out of a real sky, computed for a latitude, a date and a light-polluted limiting magnitude.
A sky computed from the catalogue for a stated place, night and hour — real positions, real magnitudes, dimmed by the air and cut by the sky's own glow. You are asked for targets: a constellation's brightest stars. Choose a star on the chart or from the list by region and name it as the target. Every wrong identification spends a probe; the probe tells you what the star really was.
Levels
5 levelsThe tag on each level says how it gets harder. Levels gate on ideas, not on each other — jump wherever it gets interesting.
What decides the outcome
The game never restates the science — it imports it. These are the model layers that do the deciding.
Precession, the equatorial-to-horizontal transform with local sidereal time, airmass extinction, the one visibility rule (`isVisibleAgainstSky`) and the magnitude-to-sprite mapping — applied to the constellation-figure star rows (VizieR IV/27A) and Bortle's naked-eye limits from Astronomy's data layer. The game states no position or magnitude of its own.
Why it teaches
The author's own delete-the-science argument: remove this game's substrate and there is nothing left to choose.
Every pick is a decision about a real sky: which bright point is Rigel and which is Sirius, why half of Orion vanishes under a city sky, why the familiar figure stands on its head from the south, why the False Cross is not the Southern Cross, and why Orion is simply not there on a July night. Without the coordinate transform and the magnitude model every level is the same scatter of dots, and no answer is any more right than another.
Accessibility
The contract's declarations, stated before you commit to a run.
Keyboard
Playable start to finish from the keyboard.
Screen reader
Every move is narrated — the narration is the state, not a description of a picture.
Motion
Reduced-motion: consequences render statically.
Audio
Silent — no sound, and nothing on screen moves on its own.