✦CHORDLIGHTTHE SHADOW SURVEY
0 / 8 surveys

A LITTLE NIGHT SCIENCE

Find the shape of
something unseen.

A star blinks out. A shadow leaves a clue.
Place your telescopes and piece together the asteroid.

01   SHADOW TRACKOBSERVATORY ONLINE
THE STAR MOVES LEFT → RIGHT
Lines show where its light disappears.
1. Choose a telescope laneNorth +4 / South −4

Start at lane 0, then look north or south for differences.

A whole silhouette, one missing star. Each telescope sees a different slice. Long, short, or no blink at all — every observation is evidence.

8 quiet puzzles · no timer · saves on this device

FIELD GUIDE

A shadow is a fingerprint.

When an asteroid passes in front of a distant star, the star briefly disappears. An observer’s track cuts a chord through its silhouette.

  1. Choose a north–south telescope lane, then Observe. Mint segments show where the star went dark. A miss is useful too.
  2. Select a candidate. Its dashed amber prediction appears on every measured lane. Look for matching endpoints and gaps.
  3. Identify the outline when you’re confident. Earn a gold seal by using no more than the suggested measurements, with no mistaken identifications or nudges.

You can measure every lane; the suggested count is a challenge, not a limit. Undo and restart are always available.

Keys: ↑/↓ choose lane · Enter observe · A–F choose outline · I identify · U undo · H nudge. Tab and Enter work on every button.

Fictional shapes and exact, noise-free measurements. This is a geometric deduction game, not an observing or safety tool.

ABOUT THIS EXPEDITION

Made for curious nights.

An original static game inspired by NASA’s October 28, 2026 Astronomy Picture of the Day on mutual occultations. Asteroid shadow-chord geometry is simplified here into a playful experiment.

Scientific GitHub research reference: vladtcvs/VOccultation, 1 star observed November 7, 2026, GPL-3.0; last push May 18, 2026. It is a Python photometry tool, not a browser game. No upstream code or assets were reused.

Game code: original, MIT. Observatory artwork: GPT image model, optimized and bundled locally. No external assets or runtime services.

Metadata tags: github-source, game. Progress stays in this browser. Read the license.