Orb of Influence

A band, not a wire

Astrologers usually give a planetary line an orb of a few hundred miles — a common working figure is up to roughly 300 miles (500 km), with the effect strongest within the first 150 and fading steadily beyond. Inside that band, the planet is close enough to an angle in your relocated chart to behave as angular; past it, the planet slips back into the ordinary ranks and the place stops carrying its signature.

Treat the numbers as honest approximations, not walls. A line 100 miles away is genuinely present weather; at 400 miles it is a distant front — occasionally felt, easily overridden by everything else in the chart.

What sharpens or softens a line

Three refinements matter. The planet's natal strength: a planet that is already loud in your birth chart projects a wider, clearer line; a quiet one whispers even directly underfoot. Crossings: where two lines intersect — or two planets angle at the same latitude, the refinement known as parans — the local weather is a blend, and often stronger than either line alone. Birth-time accuracy: the angles move about a degree every four minutes, so an uncertain birth time can slide every line by more miles than the orb forgives. If your time is approximate, read the map in broad strokes.

Using orbs practically

The practical rule: choose places, not points. A city 50 miles off your Jupiter Midheaven line receives essentially the full line; there is no need to live in a cornfield for exactitude. The free Best Place to Live tool accounts for line proximity across your whole map when it names your strongest ground — and planetary lines covers what each nearby line would actually bring.