Astrocartography online: how the map is made and how to read it
Astrocartography online draws where on Earth each of ten bodies was rising, setting, highest or lowest in the sky at your birth moment: 40 lines on a map. The lines are geometry; what a place means is tradition.
What it is
Astrocartography starts from your natal sky but asks a different question. Not what the sky looked like from your birthplace, but where on Earth each planet stood on a key point of the sky at that moment.
There are four key points, called angles. On the Ascendant (ASC) line the planet was rising on the eastern horizon. On the Descendant (DSC) line it was setting. On the Midheaven (MC) line it was at its highest point in the sky. On the Imum Coeli (IC) line it was at its lowest point, opposite the MC.
The tool draws ten bodies: the Sun, the Moon, Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. Ten bodies on four angles make 40 lines.
MC and IC lines are meridians, running straight from north to south. ASC and DSC lines are curves that follow the horizon and bend across many latitudes.
A line stops where the body would never rise or never set, and nothing is drawn beyond that point. All lines are also cut at 85° of latitude, north and south. The flat map shows the area from 60° south to 80° north.
The flat map and the globe show the same lines. On the map you can zoom and move; on the globe you can turn the planet.
“Check a city” lets you pick a city and lists the lines that pass within 500 km of it, with the distance measured over the globe to the nearest point of each line.
The lines are spherical geometry from the positions of the sky at your birth moment, so they can be checked, and our tests check them. A Midheaven line sits where the planet was on the meridian, at its highest point in the sky. Every point of a horizon line is exactly on the horizon. The distance from a place to a line differs by no more than 2 km from the distance measured on a much finer drawing of the same line.
What the tests do not include is a comparison with the maps of another astrocartography program. We have not made that comparison.
The texts that explain each line speak of themes the tradition links with places. They are general wording from the tradition, the same for everyone who gets the same line, and not written about you personally.
How it works, step by step
- Enter your date of birth and the time of birth. The time is required: the Earth turns once a day, so an hour’s difference moves every line by about 15° of longitude.
- Choose the time zone of the birthplace, or pick the city from the list. The place is used only for its time zone. The lines are for the whole world.
- Press “Draw the map”. Our server converts your local time to an exact moment, finds where the ten bodies stood in the sky and sends back ten positions and one sidereal time. Your browser draws the lines from them.
- Switch planets and angles on and off, and move between the flat map and the globe.
- Choose a line, on the map or in the list, to read about it.
- Use “Check a city” to see which lines pass within 500 km of a place.
How to read the map
Find a line, and read its two parts. The planet is the body that stood on the angle, and the angle says how: rising, setting, highest or lowest.
A city close to a line is a place where, at your birth moment, that planet stood on that angle as seen from the city.
Lines cross. Where two lines meet, both statements hold at once.
What that means for a place is a tradition. Use it as a question to ask about a place, not as an answer about it.
What it can do
- Draw 40 planetary lines for a birth moment: ten bodies on four angles.
- Show them on a flat map and on a globe you can turn.
- List the same lines as text, so they can be used without a mouse.
- List the lines within 500 km of a city, with the distance to each.
- Work for births from 1800 to 2100.
What it cannot do
- It does not predict events or tell you where to live. A line is a tradition’s idea about a place, not a forecast.
- It needs the exact birth time. Without it the lines would be in the wrong places, so the tool does not draw them.
- It draws only these 40 lines. There are no other points and no other kinds of lines.
- Lines are cut at 85° of latitude, and the flat map shows 60° south to 80° north. A city beyond the visible part is still listed with the lines near it, but it is off the map.
- The maps have not been compared with the maps of another astrocartography program.
- The texts that explain the lines are not about you personally: everyone who gets the same line gets the same wording.
Who it is for
People who know their natal chart and are curious how it looks on a map. People thinking about a trip or a move who want something to reflect on. It is not a tool for deciding where to live or work, or for decisions about health, law or money.
Questions and answers
Why does the tool need my birth time?
The Earth turns once a day, so the lines sweep a full turn of the globe in 24 hours. An hour moves every line by about 15° of longitude, and a few minutes move it by tens of kilometres. Without the exact time the lines would be in the wrong places.
What do ASC, DSC, MC and IC mean?
They are the four angles. ASC is where the planet was rising, DSC where it was setting, MC where it was at its highest point in the sky, and IC where it was at its lowest point.
Is my birth data saved?
No. Only the birth date, time and time zone are sent, once, to calculate the sky. The lines and the city check are worked out in your browser, and nothing is saved.
How accurate are the lines?
Our tests check the geometry: where the lines fall for a given sky, and how far a place is from a line. There is no comparison with another program’s maps.
Why does a line stop, or is missing?
A horizon line ends where the planet would never rise or never set at that latitude. All lines are also cut at 85° of latitude, and the flat map shows only 60° south to 80° north.
Does it tell me where to live?
No. The lines are geometry, and what a line means for a place is a tradition. Use it as a prompt for reflection, not as a recommendation.
Which dates can I use?
Births from 1800 to 2100. The year list in the tool starts at 1900.
Are the texts about the lines about me?
No. They are general wording from the tradition, the same for everyone who gets the same line, and not written about you personally.
A note
The lines on the map are geometry: they can be calculated and checked. What a line means for a place is a tradition of interpretation. Use it for reflection and entertainment, as the tool says. It is not science and not a prediction, and it does not replace medical, legal or financial advice.