Positional accuracy
±0.001″
Measured. Not guessed.
Most astrology sites round off, hand-wave, or use a spreadsheet. We use the same astronomical engine NASA mission planners use, fed by the same JPL data professional observatories rely on.
Typical accuracy± 9.999arcsec
That’s about the angular size of a quarter held five kilometres away. Computed for every planetary position in every reading.
02: The math engine
Three pieces, none of them ours.
01
Swiss Ephemeristhe engine
The gold standard for astronomical calculation. The same engine used by professional astrologers, mission planners, and academic ephemerides. Open-source, peer-reviewed, decades old.
02
NASA JPL DE441the data
Jet Propulsion Laboratory's planetary ephemeris. The same dataset used to predict where the planets will be a thousand years from now and where they were a thousand years ago. We pull positions from it.
03
± 0.001 arcsecondsthe accuracy
The typical error in a planetary position we compute. To a working astrologer, that is rounding noise. To us, it is the bar.
03: What an arcsecond is
A sky split into three million parts.
A circle is 360 degrees. Each degree is split into 60 arcminutes. Each arcminute is split into 60 arcseconds. An arcsecond is one three-thousand-six-hundredth of a degree.
Our typical error is one-thousandth of an arcsecond, roughly the angular size of a coin held five kilometres away. Below the threshold of any human observation. Above the threshold of any meaningful astrology.
03
An arcsecond
1″ = 1/3,600°
04
Sub-arcsecond
±0.001″ = 1/3,600,000°
04: Why it matters
Three places sloppy math breaks the read.
01
Saturn at 29°59' Aries.
Saturn at 29°59' Aries is a Saturn in Aries reading. Saturn at 0°01' Taurus is a Saturn in Taurus reading. Two completely different interpretations across all three traditions.
Cusp signs require the math be exact, not approximate.
02
A 1° trine, in orb.
An aspect within 1° of exact carries weight. An aspect 5° wide barely registers. Sloppy math means an applying square gets read as a separating one, which means the energy is mistaken for resolved.
Orb precision is the difference between live and dead aspects.
03
A New Moon at 23:58.
A New Moon at 23:58 UTC on the 14th falls on the 14th in London and the 15th in Sydney. Forecast windows hinge on the exact moment of exact aspect, not the approximate one.
Timezone-correct events need timezone-correct math.
05: The pipeline
From spacecraft data to your inbox.
01
NASA JPL data
We pull positions from the DE441 ephemeris, the same dataset NASA uses to navigate spacecraft.
02
Swiss Ephemeris
Your birth date, time, and place feed into the engine. Out come planetary longitudes, latitudes, and speeds.
03
Three traditions
The same positions feed three computations: Western tropical, Vedic sidereal, Hellenistic classical.
04
Synthesis & reading
Convergent and divergent themes are surfaced, then composed into the prose you read.
If precision matters to you
Read your chart through the measured engine.
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