The sky on July 21, 1947 — as it really was
That day the Sun stood in Cancer — sign and constellation agree here.
Bodies on the ecliptic (noon UTC)
- ☉︎ Sun — 117.9° · sign Cancer · constellation Cancer
- ☽︎ Moon — 164.4° · sign Virgo · constellation Leo
- ☿︎ Mercury — 107.8° · sign Cancer · constellation Gemini
- ♀︎ Venus — 105.8° · sign Cancer · constellation Gemini
- ♂︎ Mars — 74.2° · sign Gemini · constellation Taurus
- ♃︎ Jupiter — 227.7° · sign Scorpio · constellation Libra
- ♄︎ Saturn — 130.5° · sign Leo · constellation Cancer
- ☽︎ Moon 16% 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]
waxing crescent, 16% lit; the Moon was 368,216 km away.
astronomy-engine - How far Earth has travelled since [EXACT]
79.2 orbits of the Sun — 74,437 million km, that is 96,822 return trips to the Moon; 28,930 rotations of Earth; with the Sun — 574.9 billion km around the Galactic centre, 22.2 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 302 million km away; today it is 246 million km (closer by 1.2×).
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 June 5, 2028; Jupiter — in 2030.
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.