The sky on December 13, 1978 — as it really was
That day the Sun stood in Ophiuchus, while the horoscope says "Sagittarius". The gap is 23.6° of precession.
Bodies on the ecliptic (noon UTC)
- ☉︎ Sun — 261.1° · sign Sagittarius · constellation Ophiuchus
- ☽︎ Moon — 69.5° · sign Gemini · constellation Taurus
- ☿︎ Mercury — 245.8° · sign Sagittarius · constellation Scorpius
- ♀︎ Venus — 221.4° · sign Scorpio · constellation Libra
- ♂︎ Mars — 270.6° · sign Capricorn · constellation Sagittarius
- ♃︎ Jupiter — 128.5° · sign Leo · constellation Cancer
- ♄︎ Saturn — 163.8° · sign Virgo · constellation Leo
- ☽︎ Moon 99% 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]
full moon, 99% lit; the Moon was 395,995 km away.
astronomy-engine - How far Earth has travelled since [EXACT]
47.8 orbits of the Sun — 44,930 million km, that is 58,441 return trips to the Moon; 17,462 rotations of Earth; with the Sun — 347 billion km around the Galactic centre, 13.4 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 359 million km away; today it is 245 million km (closer by 1.5×).
astronomy-engine; checked against JPL Horizons for 2026-09-14 - Solar cycle [ESTIMATE]
That day fell in solar cycle 21, on the rise to maximum (27% through the cycle).
SILSO smoothed minima - When the sky repeats [EXACT]
Mars returns to that day’s point of its orbit on November 7, 2027; Jupiter — in 2037; 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 2,376″ since that day; the real constellations now sit 23.6° away from the astrologers’ “signs”.
precession 50.29″/yr
Other dates
Computed from the date only; nothing about you is stored.