The sky on December 17, 1927 — as it really was
That day the Sun stood in Ophiuchus, while the horoscope says "Sagittarius". The gap is 22.9° of precession.
Bodies on the ecliptic (noon UTC)
- ☉︎ Sun — 264.6° · sign Sagittarius · constellation Ophiuchus
- ☽︎ Moon — 191.0° · sign Libra · constellation Virgo
- ☿︎ Mercury — 252.1° · sign Sagittarius · constellation Ophiuchus
- ♀︎ Venus — 219.7° · sign Scorpio · constellation Libra
- ♂︎ Mars — 246.4° · sign Sagittarius · constellation Scorpius
- ♃︎ Jupiter — 354.9° · sign Pisces · constellation Pisces
- ♄︎ Saturn — 251.8° · sign Sagittarius · constellation Ophiuchus
- ☽︎ Moon 36% 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]
last quarter, 36% lit; the Moon was 403,977 km away.
astronomy-engine - How far Earth has travelled since [EXACT]
98.8 orbits of the Sun — 92,854 million km, that is 120,778 return trips to the Moon; 36,088 rotations of Earth; with the Sun — 717.1 billion km around the Galactic centre, 27.7 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 365 million km away; today it is 244 million km (closer by 1.5×).
astronomy-engine; checked against JPL Horizons for 2026-09-14 - When the sky repeats [EXACT]
Mars returns to that day’s point of its orbit on August 24, 2027; Jupiter — in 2034; a full moon exactly on this date — December 16, 2032
sidereal periods: Mars 686.98 d, Jupiter 11.862 yr - How far the sky has drifted since [EXACT]
The vernal point has shifted 4,968″ since that day; the real constellations now sit 22.9° away from the astrologers’ “signs”.
precession 50.29″/yr
Other dates
Computed from the date only; nothing about you is stored.