The sky on September 21, 1947 — as it really was
That day the Sun stood in Virgo — sign and constellation agree here.
Bodies on the ecliptic (noon UTC)
- ☉︎ Sun — 177.7° · sign Virgo · constellation Virgo
- ☽︎ Moon — 259.5° · sign Sagittarius · constellation Ophiuchus
- ☿︎ Mercury — 195.4° · sign Libra · constellation Virgo
- ♀︎ Venus — 182.5° · sign Libra · constellation Virgo
- ♂︎ Mars — 114.3° · sign Cancer · constellation Gemini
- ♃︎ Jupiter — 233.8° · sign Scorpio · constellation Libra
- ♄︎ Saturn — 138.1° · sign Leo · constellation Leo
- ☽︎ Moon 43% 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, 43% lit; the Moon was 399,672 km away.
astronomy-engine - How far Earth has travelled since [EXACT]
79 orbits of the Sun — 74,277 million km, that is 96,615 return trips to the Moon; 28,868 rotations of Earth; with the Sun — 573.7 billion km around the Galactic centre, 22.1 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 256 million km away; today it is 245 million km (closer by 1×).
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 6, 2028; Jupiter — in 2030; a full moon exactly on this date — September 20, 2040
sidereal periods: Mars 686.98 d, Jupiter 11.862 yr - How far the sky has drifted since [EXACT]
The vernal point has shifted 3,960″ since that day; the real constellations now sit 23.1° away from the astrologers’ “signs”.
precession 50.29″/yr
Other dates
Computed from the date only; nothing about you is stored.