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From Earth, the Tychonic and heliocentric models predict the same planet directions — toggle the frame to see the diagram move while the sky does not.

100%

Green dashed lines are sight lines from Earth — they never change when you toggle models. Pinch to zoom, drag to pan. Tap a planet in the panel or sky strip to highlight one.

Earth at center — epicycle paths
Speed, zoom & trails
1 second = 1 day
Zoom: 100%
Scroll on the chart to zoom
Epicycle paths in Tychonic view
Observations from Earth

Observations from Earth — identical in both models

Toggle Heliocentric ↔ Tychonic — the observation panel does not change. Sight lines from Earth never change. Click a row to highlight one planet.

Night sky strip

Night sky — azimuth from Earth (same in both models)

N · 0° E · 90° S · 180° W · 270°

Direction in the orbital plane — compass azimuth, 0° north through east. Updates with the date and speed controls above.