Calculation notes
& source.

This app calculates geocentric ecliptic longitudes and longitudinal speeds using Swiss Ephemeris through swisseph-wasm 0.1.0. Vedic mode sets SE_SIDM_LAHIRI. Houses use the Swiss whole-sign system W. Mean lunar node is Rahu; Ketu is exactly 180° opposite Rahu. Outer planets are optional.

Birth local time is converted using the explicitly entered UTC offset. No historical timezone lookup is performed. City presets fill approximate city-centre coordinates and standard UTC offsets; verify the historical offset, including daylight saving, for the birth date. Dates supported by this UI: 1800–2399. The wrapper packages ephemeris files and the Swiss engine may fall back to Moshier where applicable; the JSON export includes per-call returned ephemeris flags and warnings. High precision numerical display should not be confused with independent accuracy certification.

The animated explorer

Natal+transit mode keeps the natal Ascendant and whole-sign houses fixed. Moment mode recalculates both at the selected instant and supplied location. During playback, each animation frame recalculates positions. Manual date jumps ease between the old and new display positions; numeric values immediately show the newly calculated result. The wheel displays longitudes, not orbital distances. House sectors are equal 30° whole signs. The Ascendant is marked within house 1. MC is shown numerically and need not be in house 10.

Traditional nakshatras divide the sidereal zodiac into 27 segments of 13°20′, each with four padas. These are shown only in sidereal mode. Direct / retrograde uses the sign of longitudinal speed. Applied birth details are shared with the explorer in the current tab’s session. Remembering them across visits is optional. Existing saved profiles remain available until removed. This browser storage is not encrypted. From and To are editable date/time fields using the displayed UTC offset. Apply dates updates the scrubber and playback interval; playback stops at To and replay restarts at From. Video export captures the selected 2D or 3D canvas for up to 12 seconds or the end of the interval, then restores the original date.

Aspects, compatibility & Moon phases

Birth aspects use the seven classical planets and a uniform 6° maximum orb. Compatibility uses those same seven planets in each chart, with a selectable 3°, 6° or 8° orb. Supported angles are 0°, 60°, 90°, 120° and 180°. Results are sorted by distance from the exact angle. House overlays use each person's whole-sign chart. These are Western angular aspects in either zodiac setting; this is not Vedic guna matching.

Moon illumination and phase angle come from Swiss Ephemeris pheno_ut. Phase labels use normalized geocentric Sun–Moon ecliptic longitude difference, with a 1° window for new, full and quarter labels. The lunar calendar samples each date at 12:00 UTC. The disc is a schematic with waxing illumination on the right; its local orientation is not calculated.

The 3D view

The 2D / 3D switch uses the same Swiss Ephemeris positions and date controls. The 3D map is Earth-centered: each physical body’s calculated geocentric ecliptic longitude and latitude supply its direction. Both views use evenly spaced schematic tracks, and body sizes are illustrative. Ring guides are display tracks, not physical distances or calculated orbital paths. Actual distance in AU is shown in the 3D chips. Larger symbols may move slightly to avoid overlap; a small anchor and leader keep the calculated position visible. Moving chips show sign, degree, motion and house in both views. The house sectors are divisions of ecliptic longitude in the selected whole-sign frame, not physical rooms in space. Transits keeps natal houses; This moment uses the selected moment’s houses. Rahu and Ketu are displayed as calculated points, not physical planets. Background specks are decorative. Drag, pinch, scroll or use the camera buttons to change the view; this changes the camera, not the chart data.

Planet placement readings

Click a planet or its moving chip in either view to pause the timeline and open its explanation. The keyboard-accessible planet list, selector and Enter key on the chart open the same details. Transits use fixed natal houses; Birth chart uses natal positions; This moment uses the selected instant’s houses. Exact displayed coordinates come from the calculation engine. Interpretation is original, authored content that combines a planet-specific house description with house themes, sign symbolism and motion. These are symbolic traditions, not scientifically established effects or predictions. The app does not calculate a complete personalised judgement from dignity, aspects, house rulerships or dashas. Classical bodies use shared introductory themes, Rahu and Ketu use Vedic node symbolism, and outer planets use modern Western symbolism in either zodiac mode. Introductory references: Astrodienst’s house guide and planet guide.

The original planet illustrations use a school-textbook visual language: surface colours, clouds, bands and rings. They are illustrative artwork, not NCERT reproductions or calculated views of phase, axial orientation or surface features. The Sun is a star, the Moon a natural satellite, Pluto a dwarf planet, and Rahu/Ketu calculated nodes. NCERT: Beyond Earth provides introductory astronomical context. Light/dark appearance is shared across all pages and both chart views. Film exports use the selected appearance.

Learning

Reflection prompts and course lessons are authored content, not LLM outputs. This app has no AI backend, dasha engine, secondary-progressions engine or divisional charts yet. No birth details are sent to an AI provider. Astrology Foundations has a complete free 12-lesson short course with knowledge checks and a personal notebook. The other seven courses have starter lessons and planned outlines; their full lesson libraries and paid enrollment are not available.

License & inspectable source

The original application source is offered under AGPL-3.0-or-later. Third-party wrapper licensing is GPL-3.0-or-later; Swiss Ephemeris is dual licensed under AGPL or a professional license. The upstream author’s licensing text is retained; Astrodienst’s official terms govern the underlying engine.

Official Swiss Ephemeris documentation · WASM wrapper source · AGPL license

The vendor wrapper exposes returned flags and warnings from calc_ut and uses a corrected 20-double buffer and error pointer for pheno_ut. The project repository requires access. The application modules delivered to your browser can be inspected below. Application source: explorer · engine · aspects & Moon · tools · design. Vendor source: wrapper · WASM loader · WASM binary · ephemeris data · wrapper license.