The sky on December 21, 1973 — as it really was
That day the Sun stood in Sagittarius — sign and constellation agree here.
Bodies on the ecliptic (noon UTC)
- ☉︎ Sun — 269.5° · sign Sagittarius · constellation Sagittarius
- ☽︎ Moon — 235.3° · sign Scorpio · constellation Libra
- ☿︎ Mercury — 258.9° · sign Sagittarius · constellation Ophiuchus
- ♀︎ Venus — 308.3° · sign Aquarius · constellation Capricornus
- ♂︎ Mars — 29.2° · sign Aries · constellation Aries
- ♃︎ Jupiter — 312.2° · sign Aquarius · constellation Capricornus
- ♄︎ Saturn — 91.4° · sign Cancer · constellation Gemini
- ☽︎ Moon 9% 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 crescent, 9% lit; the Moon was 400,497 km away.
astronomy-engine - How far Earth has travelled since [EXACT]
52.8 orbits of the Sun — 49,607 million km, that is 64,525 return trips to the Moon; 19,280 rotations of Earth; with the Sun — 383.1 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 113 million km away; today it is 246 million km (farther by 2.2×).
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 July 7, 2028; Jupiter — in 2032; a full moon exactly on this date — December 20, 2029
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.