TRANSITS · LONGITUDES AND ANGLES
The sky now and
the sky when you were born
Transits compare celestial positions at a chosen moment with positions at birth. This screen calculates ten bodies' longitudes and deviations from five aspect angles. There is no universal orb threshold; three are shown without interpreting aspects or future events.
LONGITUDES AND ANGLES
Calculation results
Celestial longitudes
| Celestial body | Moment of birth | Comparison moment | Movement that day |
|---|
Aspect
| Bodies (comparison moment → birth moment) | Aspect | Difference from exact aspect | Orb threshold |
|---|
How was this calculated?
Celestial positions
We use apparent geocentric true-ecliptic longitude from Astronomy Engine (MIT), including light travel time but not atmospheric refraction. Tropical and sidereal sign names differ, so only angles are shown. Their coordinate offset applies equally to every body and does not change the angle between them.
Aspects and orbs
We measure deviation from conjunction 0°, sextile 60°, square 90°, trine 120° and opposition 180°. Sources differ on allowable orbs. This screen shows 0°, 3° and 6° thresholds without selecting one. For example, practitioner sources Astrotheme and TimePassages use 8.3° and 8° for trines.
What was and was not verified
- Engine longitudes were checked against JPL Horizons (DE441) at 34,970 times sampled every seven days in 1960–2026. All ten bodies differed by less than one arcminute (1/60°); the largest difference was Venus at 20.4 arcseconds.
- Seven-day sampling does not verify every intervening time. This comparison does not establish latitude, distance or retrograde status.
- Orb thresholds have no universal standard. Sources vary; Lilly's 1647 method assigns widths by body rather than aspect and is not calculated here.
- If birth time is unknown, local noon is used and the Moon is excluded from aspects because it moves about 13° daily. Each body's daily movement is also shown.
- Ascendant, houses, retrograde motion, applying/separating aspects and exact-aspect dates are not calculated.
- This comparison measures positional calculation differences only; it does not establish the validity of astrological interpretation.