Positions,
not predictions.
We don’t tell you what the stars say. We compute where they are. A reference for the astronomical ephemeris and the cultural language built around it, cited per tradition.
23 hubs
Privacy-first natal chart calculator. Ascendant, planets, whole-sign houses, aspects — all computed in your browser.
Open →Transit chart calculator. Current planets in natal houses, applying / separating aspects to natal points.
Open →Solar return calculator. Finds the exact annual Sun return moment, computes the return chart for any chosen year.
Open →Synastry calculator. Two-chart aspect grid and house overlay for relationship reference.
Open →Composite calculator. Midpoint of two natal charts — composite Sun, Moon, planets, ASC and MC.
Open →Natal Sun signs and planetary positions for notable figures, computed from the ephemeris. Browse by sign or field.
Open →Twelve zodiac sign references — dates, elements, modalities, rulers, traditional meanings cited per tradition.
Open →Ten planets plus Chiron and the lunar nodes — dignities, cycles, retrograde periods.
Open →Twelve astrological houses — modern keyword, Hellenistic name, classification, and natural ruling sign.
Open →Moon phases, lunar quarters, mercury retrograde — astronomical calendar.
Open →Daily planet positions 2020-2035 — full ten-body tables by month.
Open →Current planetary positions and moon phase. Updated hourly.
Open →The premise
Computation, not prediction. Ephemeris values are astronomical measurements — verifiable against NASA JPL Horizons. Interpretive material is cultural reference, framed as “traditionally associated with”, never as personal advice.
Cited per tradition. Hellenistic, medieval, modern Western, and Vedic interpretations differ on the same chart factor. Every interpretive page names which tradition it cites.
Privacy first. Birth data never leaves the browser. Charts compute client-side, share via URL only.
Part of otldr
astro.otldr.com is the astronomy vertical of the otldr network. Same publisher, same policies as the cars and other verticals.