Transit — a later sky against a natal chart

The ephemeris route takes a natal date, natal coordinates, an optional transit date, and a house system. It builds the natal chart, then compares. This is different from the public sky map, which has no natal chart at all. The sky map on a sign page only answers “which bodies are inside this 30° window right now.”

A daily horoscope that names a transit should be able to name the two bodies and the aspect. “Mars square natal Sun” is a 90° test with an 8° orb between today’s Mars and the birth Sun. A sentence that only names the sun sign is not that test. The sign pages stay on the sign’s fixed geometry plus the current sky slice so they are not fake personal transits.

Because transits move, a page that froze yesterday’s aspect into static copy would go stale. The sign pages recompute the sky slice on a one-hour cache instead of publishing a transit essay per sign.

Example: natal Sun at 15.0° Aries, today’s Mars at 108.0°. The folded gap is 93°, which is 3° from a square and inside the 8° orb, so Mars squares the natal Sun. Today’s Mars at 40.0° is 25° from that Sun, inside no orb in the table. A sign page cannot print this, because it does not know the 15.0° natal figure. It can only say whether Mars is currently inside some 30° window. The transit route is the one that keeps both longitudes.