The Relocated Chart, Local Space and the History of Astrocartography

An astrocartography map is the most visible form of locational astrology, but it is not the only one, and it is not the most complete. This article covers the relocated chart that stands behind every line, the local space technique that asks about directions rather than places, the history of both, the question of tropical and sidereal zodiacs, and the practical matter that decides how far any of it can be trusted: the accuracy of the birth time.

The relocated chart

A line on the map says that at some longitude a particular body was exactly on an angle. The relocated chart says what the whole chart looks like once you stand there, and it is the more complete answer, because a place changes far more than the one line you noticed.

What moves

Recasting the chart for a new place moves the Ascendant and Midheaven, and moving them renumbers every house. A body that was quietly in your twelfth house at birth can be sitting on the Midheaven a thousand kilometres east. Nothing about the body changed. The frame it is being measured against did. The rulers of the angles can change too: a new rising sign brings a new chart ruler for that place.

What never moves

This is worth stating flatly because the technique is often described badly: relocation does not change your Sun sign, your Moon sign, your aspects, or any planet’s degree or dignity. Those are properties of the moment, and the moment is fixed forever. Anything claiming otherwise has misunderstood what is being recomputed.

North and south

One consequence surprises almost everyone. The Midheaven depends only on longitude, so travelling due north or due south, a thousand kilometres or five thousand, leaves it exactly where it was. Only the Ascendant answers to latitude. It is the same fact that makes the meridian lines on the map straight and the horizon lines curved, seen from the other side.

Reading a relocated chart uses nothing new: the same angles, houses, rulers and aspects as the natal chart, measured against a different horizon and meridian.

Local space

Astrocartography asks where on Earth a body was angular. Local space asks a different question with the same data: from your birthplace, in which direction was each body standing?

A compass bearing for every body

The answer is a compass bearing, the azimuth. The Sun might have been 118 degrees east of north, that is east-southeast, and low in the sky; Saturn might have been behind you to the northwest and below the horizon. Every body gets a bearing, and the set of them is a fan of lines radiating from one point on the map.

How it is read

It is read for movement rather than for places. Travelling or moving along a body’s direction is held to carry you further into what that body means, and the technique is also used at the scale of a single building or room: which way the desk faces, which wall the bed is against. Michael Erlewine set it out in this form in the 1970s.

Great circles, not compass courses

The lines drawn on the map are great circles, not compass courses. Holding one bearing on a compass all the way spirals towards a pole and does not actually point at anything; the great circle is the direction something genuinely lies in. That is why a local space line leaving London towards the east crosses the map far north of where a ruler laid on the paper would put it. The bend is the Earth, not the drawing.

The two techniques agree

The two techniques agree with each other, and it is a useful check that they do. Stand anywhere on a body’s Midheaven line and its local space bearing from that spot is due north or due south, because being on the meridian is exactly what both statements mean.

Where the technique comes from

It is worth being clear that astrocartography as a map is modern. Ptolemy did not draw one. The mapped form was developed and named in the mid-1970s by Jim Lewis, who worked out the projection, published the maps and built the practice around them. AstroCartoGraphy is a registered name for Lewis’s own product; the general technique is usually called astrocartography or astrolocality. The local space technique was set out in the same decade by Michael Erlewine, and Bernadette Brady’s later work on fixed stars put the paran latitudes back at the centre of the reading.

What is old is everything the map is read with. Relocating a chart to a new place is classical procedure. The idea that a body on an angle is emphasised is as old as Hellenistic astrology and is the basis of half of it. The rule that the Sun and the Midheaven govern standing and employment comes from the fourth book of Ptolemy’s Tetrabiblos. Parans themselves, stars rising or culminating together, belong to ancient astronomy and astrology long before they were drawn on a map.

So the honest description is a twentieth-century picture of a very old doctrine. That combination is common enough in astrology, and there is no reason to disguise it in either direction: neither by claiming an ancient pedigree the map does not have, nor by presenting the readings as though somebody invented them fifty years ago.

Tropical, sidereal, and the map

Astrology is practised in two zodiacs. The tropical zodiac, standard in the West, begins at the spring equinox: the point where the Sun crosses the celestial equator going north. The sidereal zodiac, standard in Indian astrology, begins from the fixed stars, and the two have drifted about 24 degrees apart over two millennia because the Earth’s axis slowly wobbles, the precession of the equinoxes. The amount of that difference at a given date is called the ayanamsa.

What that means for the map is: nothing at all. Every line is computed from a body’s right ascension and declination, which are positions in the sky, not positions in a zodiac. Where the Sun culminates on a given date is a fact about the Earth’s rotation, and no choice of zodiac moves it by a single kilometre. A Vedic astrologer and a Western one would draw the identical map.

What changes is what is said about it. The sign a body occupies, its rulerships and dignities, and the entire apparatus of interpretation shift by those 24 degrees. So the two traditions agree completely about where your Sun line runs, and can disagree about what the Sun is doing in your chart in the first place. Indian astrology also brings tools of its own that have no counterpart on a Western map, such as the twenty-seven nakshatras and the Vimshottari dasha periods.

Birth time: the error that matters

The precision of modern astronomical calculation is not the limiting factor in astrocartography. Even a modest calculation places the planets to within a few arcminutes, and on the map an arcminute of sky is roughly two kilometres of ground. That is invisible next to an orb of a hundred kilometres.

The error that actually matters is in the birth time, and it is not small. The Earth turns 15 degrees of longitude in an hour, so one minute of clock error slides every meridian line a quarter of a degree sideways: about 28 kilometres at the equator and around 19 at mid-latitudes. Ten minutes of uncertainty moves your lines by around two hundred kilometres.

An hour matters far more on a map than in a chart. An hour of error slides every meridian line fifteen degrees: about 1,200 kilometres at European latitudes and 1,670 at the equator. A Jupiter line you were reading through Lisbon becomes a Jupiter line through Warsaw. The rising and setting lines move with it, and change shape as well, because their curve depends on where the sky met the horizon.

The clock as it read

The birth time should be taken exactly as the clock at the birthplace read it, and then converted using the history of that place: its time zone and whether summer time was in force on that date. The commonest way to get a map wrong is to help. Someone born at half past four on a July morning knows the clock was an hour ahead, subtracts the hour, and the calculation then subtracts it again.

The correction is a matter of history, not of rule. Zagreb in July 1976 was one hour ahead of universal time, because Yugoslavia kept no summer time until 1983; the same clock reading in July 1990 was two hours ahead. That is why a place is best given as a zone with its history, such as Europe/Zagreb or America/New_York in the standard time-zone database, rather than as a fixed offset. An offset is a number that was true on one date. A zone is a place with a history, and only the history can answer for a birth in 1943, or in a country that changed its mind twice in a decade.

Reading to the right precision

So the order of work is the reverse of what people expect. Verify the hour before you take any line seriously. If the recorded time is good only to the nearest hour, read the map as a set of broad regions rather than as a set of cities. The lines can always be computed to the metre, because that is what arithmetic does. Believing them to the metre is the reader’s mistake to avoid.