◈ The Terra Plana Model
A working orrery of the enclosed plane
This instrument renders the cosmos as the ancients mapped it and as modern plane-earth cosmographers refine it: a stationary circular Earth centred on the North Pole, ringed by the Antarctic ice wall, beneath a revolving firmament of stars.
Yet every luminary here is placed by a real astronomical ephemeris. The sub-solar and sub-lunar points, the planets, eclipses, phases and meteor radiants are computed to the second, then projected onto the plane through the azimuthal-equidistant mapping — the true shape of the disc.
How the plane is drawn
- Latitude → radius. The North Pole sits at the centre; the equator is the mid-circle; the southern ice wall is the rim. Colatitude maps linearly to distance.
- The Sun & Moon are near luminaries, ~ a few thousand miles aloft, circling above the plane. Their spotlight makes local day and night without any horizon curving away.
- Seasons are the sun spiralling between the Tropic of Cancer (June, a tight inner circle) and the Tropic of Capricorn (December, a wide outer circle).
- Stars ride the firmament dome — a vault that springs from just beyond the ice wall and crests over the pole. Polaris sits at the apex; southern stars wheel low near the rim. Nothing in the heavens ever passes beneath the plane.
- The Ice Wall — Antarctica — is not a continent but a 360° barrier of ice enclosing the sea.
Controls
- Space play / pause · ← → step time · R reverse flow
- Drag orbit · Scroll zoom · Right-drag pan · H hide panels
- Pick a preset to leap to the next eclipse, solstice, full moon or meteor shower.
- Choose an observer city to read the true local altitude of sun and moon.
note Positions via Astronomy Engine (VSOP87 / ELP2000-class accuracy). The geometry is the flat-earth projection; the timings are the heavens' own.