The ecliptic, unrolled — the Sun's apparent path through the sky, 0–360°. Every chart below is this band, folded. Planet positions are illustrative, not today's sky.
The observation deck
Why geocentric isn't wrong
Heliocentric is the mechanism — the Sun at the centre, planets in orbit, the model that predicts. Geocentric is the observation deck — where an observer actually stands. A chart is not a diagram of the solar system; it is a record of what the sky looked like from a place. Neither frame contradicts the other, the way a map of the rail network doesn't contradict the view from the train window.
From that deck, the Earth's rotation — anti-clockwise, seen from above the north pole — sets the apparent drift of everything along the ecliptic. And every planet in this system is one you can see with your own eyes: Sun, Moon, Mercury, Venus, Mars, Jupiter, Saturn. That is the whole reason the list stops at Saturn. This notation was fixed long before telescopes; it records the visible sky, and only the visible sky.
The signature move
The fold — one marker, three charts
Below is one gold marker on the band, and one dawn-blue ascendant — the लग्न lagna, the degree rising on the eastern horizon. Drag the marker, or use the sliders. All three charts move at once, because all three are reading the same number. That simultaneity is the entire point.
Western · circle
Ascendant pinned to the left horizon; the zodiac turns.
South Indian · square
Signs nailed to boxes; the lagna mark travels.
North Indian · diamond
Houses nailed to positions; the signs travel.
Reading each frame
Same sky, three grammars
fixed: ascendant · moving: signs
Western — the circle
The ascendant sits at the left horizon, always. Houses run anti-clockwise from it — 1 through 6 below the horizon, 7 through 12 above. Move the ascendant slider and watch the zodiac ring rotate while the frame holds still.
fixed: signs · moving: lagna
South Indian — the square
Twelve boxes in a fixed ring — Aries always second from top-left, Pisces always the corner before it. The lagna mark moves from box to box instead. Reading order runs clockwise: the reversal against the other two frames. You have seen this grid before — the Bhavas index is drawn in it.
fixed: houses · moving: signs
North Indian — the diamond
House 1 is always the top-centre diamond, numbering anti-clockwise, with the sign written inside as a number. The kendras — houses 1, 4, 7, 10 — land on the four centre diamonds, which is why they read instantly. That is this format's actual argument for itself.
Two honest footnotes
Houses here are whole-sign: house 1 is the entire sign the ascendant occupies, house 2 the next sign, and so on. It keeps the mapping identical across all three frames and sidesteps a house-system debate this page is not trying to have. And the planet positions are illustrative, set by you — nothing on this page is calculated for a date, and nothing on it interprets anything. For the sky read fortnightly, there is Antara.