Runs on your device

Engine demo

This is the real astronomy and rendering core, not a video. Positions are computed with Astronomy Engine and drawn with WebGL2 in your browser. Nothing is sent to a server — no frames, no location, no account.

What is real here

  • • Topocentric bearing, altitude and angular size for the selected time and place.
  • • Live keeps natural angular size; Grandeur enlarges while keeping the bearing.
  • • A body below the horizon stays unavailable in the grounded modes.
  • • Changing the time genuinely recalculates positions.

What is not

  • • Viewing is manual. The browser has no compass or world tracking here.
  • • The camera cut-off is a horizontal slider, not sky segmentation.
  • • Planet surfaces are procedural illustrations, not observed imagery.
  • • The black hole is an imagined scene, not a physical simulation.

Needs a current browser with WebGL2. Camera preview and location need a secure context and your explicit permission; if either is unavailable the demo falls back to the manual panorama and says so.