Astrocartography takes your birth chart and draws it on the world map. Instead of asking which house a planet fell in for the city where you were born, it asks: in which places on Earth would that planet be on one of the four angles, at the exact instant of your birth?

The answer is a line across the globe. For each planet there are four: where it would be rising on the eastern horizon, where it would be setting in the west, where it would be at the top of the sky and where it would be at the lowest point. They are the same four positions the Ascendant, the Descendant, the Midheaven and the Imum Coeli hold in an ordinary chart, seen from every place on Earth at once.

It also goes by another name: locational astrology. It is the same thing.

The culmination lines are straight and vertical on the map, meridians. A planet culminates over one geographic longitude, and over the whole of it: from the north pole to the south pole, every point on that longitude has the planet at the top of the sky at that instant. There are two per planet, the high one and the low one, always half a turn apart.

The rising and setting lines are curves. The longitude where a planet sits exactly on the horizon depends on the latitude you are looking from, and the calculation that gives it is the same semi-diurnal arc this site’s engine already uses for the houses.

The practical consequence of the difference: a culmination line cuts the whole continent in a straight line; a horizon line winds, and can pass close to two cities very far apart.

There are four lines per body. With the ten planets, forty, and this site also draws Chiron and the North Node, which takes it to forty-eight on the delivered map.

Forty-eight lines on a globe of 360 degrees of longitude is a lot of line. Twenty-four of them are meridians, which gives one every fifteen degrees on average: a little over 1,600 kilometres at the equator, and less than that as you go north or south. Measured across 4,000 charts drawn at random between 1930 and 2025, with the ten planets:

In São Paulo, the nearest line is 320 km away at the median, there are on average 2.18 lines within 1,000 km, and 8.5% of charts have none within 1,000 km; in Belém, 329 km, 2.01 lines and 10.1%; and in Porto Alegre, 288 km, 2.31 lines and 7.1%.

Having a line near you is the common case, not a sign. Nine in ten charts have some planetary line within a thousand kilometres of São Paulo, and half have one within 320. A site announcing "you have a Jupiter line running through your state" is announcing the normal.

What sets one chart apart from another is not having a line nearby, it is WHICH line, of what kind, and at what distance compared with the others. That is why a serious reading measures the distance to each one instead of listing the ones that "pass nearby".

The reading of a line combines two things: the planet and the angle it is on.

• At the top of the sky, the planet’s subject shows up in public life, at work and in reputation. It is the angle most associated with career.
• At the lowest point, the same subject, but at home, in the family and in private life. It is the angle for anyone looking for a root.
• Rising, the planet enters the way you arrive: how you are seen and how you present yourself in that place.
• Setting, it enters through the other person: through partnerships, encounters, whoever shows up in your life there.

That is why the same city can be excellent for one thing and heavy for another. A Venus line on the angle of the other person describes a place where relationships open up; the same Venus at the top of the sky describes a place where your work has to do with beauty, with taste or with money. It is not the same advice.

Astrocartography does not change your birth chart. The sky of your birth belongs to an instant that has passed, and no change of address rewrites it. The planets stay in the same signs and the same aspects wherever you go; what turns is the Ascendant, and with it the houses.

It also does not promise a result. A line describes what comes to the front in a place, not whether it will work out. Living on a Mars line does not guarantee courage nor condemn you to arguments: it guarantees that Mars’s subject will be awake there.

And it does not decide anything for anyone. A job, a family, money and a visa still exist, and they weigh more than any line. Astrocartography comes in as one more piece of information in a decision that is yours, and that is how it is worth using.