A moment
in the sky.

Ten bodies, the tropical zodiac, and geocentric apparent ecliptic longitudes of date. Signs are twelve equal 30° divisions beginning at the March equinox; they are not the unequal astronomical constellations. “Planets” here includes the Sun, Moon and Pluto as a conventional chart grouping.

Astronomy Engine 2.1.19 has a stated accuracy target of roughly one arcminute. We display positions to 0.1°, mark sign and house boundary cases within 0.02°, and estimate apparent retrograde motion from a one-hour difference. Numerical accuracy does not imply that an interpretation is accurate.

Porphyry trisects the four ecliptic quadrants between the ascendant and midheaven axes. Whole sign assigns a complete 30° sign to each house. The chosen convention is always shown; neither is established as a scientifically superior personality model. Angles and houses are withheld at latitudes of 66° or higher in either hemisphere.

The local date, time and birthplace time zone determine the UTC instant. Daylight-saving gaps are rejected; repeated times require you to choose an occurrence. Time-zone history comes from the browser’s IANA-based data through Temporal; older records, especially before 1970, may need independent checking.

Approximate times are sampled at intervals of no more than five minutes. Positions and possible sign or house changes are shown across that interval. If the time is unknown, we cover the entire local day and hide the ascendant and houses. A midpoint is only a plotting reference. These are sampled ranges, not statistical confidence intervals or exact transition searches.

GeoNames supplies city centres and IANA zone names. A city centre is not a precise birth address, and the dataset is not a complete historical gazetteer. Manual coordinates and zone correction are available.

The reading vocabulary contains 120 original planet–sign entries and 12 rising-sign entries. Each planet reading separates symbolic style, house context and connected aspects. Six life areas gather these same placements using disclosed body and house rules. Uncertain signs or houses do not receive a definite interpretation.

We show five major aspect types. The maximum angular deviation is 6° for conjunctions, squares, trines and oppositions, and 4° for sextiles. These thresholds are editorial conventions, not probabilities. Aspect rows are ordered by distance from the exact angle, not by an alleged measure of influence. Only aspects present at the reference time are listed; with uncertain times their stability across samples is marked.

No generative personality verdicts, compatibility scores or event forecasts are inferred. Outer-planet placements often span cohorts; they should not be treated as uniquely personal traits. We borrow Co–Star’s clear hierarchy and documented conventions, not its proprietary analysis engine or writing.

Element and modality counts include each of the ten bodies once. Uncertain signs are excluded and named. These describe a chart’s composition; they are not personality percentages. House rulers use traditional assignments, with modern alternatives labelled separately. Cusp degrees and rulers refer to the reference time.

The Transits view compares ten moving bodies with ten fixed natal positions at a selected UTC moment, using the five major aspects with a 2° limit. The initial snapshot is taken when the chart is calculated. Changing the UTC date or time recalculates it; the app does not update it in the background.

Applying and separating are estimated from a one-hour difference around the selected time. Near a turn, this label may change. The lunar phase name is a broad 45° elongation sector, not a precise new/full-moon event. No event start or end dates are inferred. For uncertain birth times, each contact’s angular range is checked; contacts not present at the natal reference time may be absent from the list.

Bruce Scofield’s The Nature of Astrology (2023) proposes a systems-science account; Bernadette Brady explores chaos and complexity in astrology. These are perspectives to examine, not established evidence that birth charts predict personality.

Here, a systems approach means explicit inputs, reproducible calculations, visible relationships and sensitivity to uncertainty. Established solar or lunar effects in nature do not, by themselves, validate astrological interpretations of an individual.