The sky on December 18, 1939 — as it really was
That day the Sun stood in Sagittarius — sign and constellation agree here.
Bodies on the ecliptic (noon UTC)
- ☉︎ Sun — 265.7° · sign Sagittarius · constellation Sagittarius
- ☽︎ Moon — 351.6° · sign Pisces · constellation Pisces
- ☿︎ Mercury — 244.4° · sign Sagittarius · constellation Scorpius
- ♀︎ Venus — 291.5° · sign Capricorn · constellation Sagittarius
- ♂︎ Mars — 348.9° · sign Pisces · constellation Aquarius
- ♃︎ Jupiter — 359.8° · sign Pisces · constellation Pisces
- ♄︎ Saturn — 24.5° · sign Aries · constellation Pisces
- ☽︎ Moon 47% 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]
first quarter, 47% lit; the Moon was 404,044 km away.
astronomy-engine - How far Earth has travelled since [EXACT]
86.8 orbits of the Sun — 81,574 million km, that is 106,105 return trips to the Moon; 31,704 rotations of Earth; with the Sun — 630 billion km around the Galactic centre, 24.3 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 175 million km away; today it is 244 million km (farther by 1.4×).
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 May 12, 2028; Jupiter — in 2034; a full moon exactly on this date — December 17, 2051
sidereal periods: Mars 686.98 d, Jupiter 11.862 yr - How far the sky has drifted since [EXACT]
The vernal point has shifted 4,356″ since that day; the real constellations now sit 23° away from the astrologers’ “signs”.
precession 50.29″/yr
Other dates
Computed from the date only; nothing about you is stored.