The sky on December 13, 1973 — as it really was
That day the Sun stood in Ophiuchus, while the horoscope says "Sagittarius". The gap is 23.5° of precession.
Bodies on the ecliptic (noon UTC)
- ☉︎ Sun — 261.3° · sign Sagittarius · constellation Ophiuchus
- ☽︎ Moon — 129.4° · sign Leo · constellation Cancer
- ☿︎ Mercury — 246.8° · sign Sagittarius · constellation Scorpius
- ♀︎ Venus — 303.9° · sign Aquarius · constellation Capricornus
- ♂︎ Mars — 27.2° · sign Aries · constellation Pisces
- ♃︎ Jupiter — 310.6° · sign Aquarius · constellation Capricornus
- ♄︎ Saturn — 92.1° · sign Cancer · constellation Gemini
- ☽︎ Moon 83% illuminated
astronomy-engine ephemerides (VSOP87/ELP), IAU 1930 constellation boundaries. Positions accurate to a fraction of a degree.
The day’s dossier, from real data
Checkable facts with a tag and a source; the classical reading is in the chart.
- The Moon that day [EXACT]
waning gibbous, 83% lit; the Moon was 363,776 km away.
astronomy-engine - How far Earth has travelled since [EXACT]
52.8 orbits of the Sun — 49,628 million km, that is 64,553 return trips to the Moon; 19,288 rotations of Earth; with the Sun — 383.3 billion km around the Galactic centre, 14.8 light-days.
29.78 km/s along the orbit; 230 km/s around the Galactic centre - Mars then and now [EXACT]
On that day Mars was 103 million km away; today it is 245 million km (farther by 2.4×).
astronomy-engine; checked against JPL Horizons for 2026-09-14 - Solar cycle [ESTIMATE]
That day fell in solar cycle 20, on the decline (81% through the cycle).
SILSO smoothed minima - When the sky repeats [EXACT]
Mars returns to that day’s point of its orbit on June 29, 2028; Jupiter — in 2032; a full moon exactly on this date — December 13, 2046
sidereal periods: Mars 686.98 d, Jupiter 11.862 yr - How far the sky has drifted since [EXACT]
The vernal point has shifted 2,628″ since that day; the real constellations now sit 23.5° away from the astrologers’ “signs”.
precession 50.29″/yr
Other dates
Computed from the date only; nothing about you is stored.