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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.

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

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 — azimuth from Earth (same in both models)

N · 0° E · 90° S · 180° W · 270°

Horizon strip at the ecliptic — compass azimuth, 0° north through east. Updates with the date and speed controls above.