The sky on July 21, 1931 — as it really was
That day the Sun stood in Cancer — sign and constellation agree here.
Bodies on the ecliptic (noon UTC)
- ☉︎ Sun — 117.8° · sign Cancer · constellation Cancer
- ☽︎ Moon — 198.3° · sign Libra · constellation Virgo
- ☿︎ Mercury — 138.9° · sign Leo · constellation Leo
- ♀︎ Venus — 104.5° · sign Cancer · constellation Gemini
- ♂︎ Mars — 173.2° · sign Virgo · constellation Virgo
- ♃︎ Jupiter — 120.9° · sign Leo · constellation Cancer
- ♄︎ Saturn — 289.4° · sign Capricorn · constellation Sagittarius
- ☽︎ Moon 42% 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, 42% lit; the Moon was 369,792 km away.
astronomy-engine - How far Earth has travelled since [EXACT]
95.2 orbits of the Sun — 89,473 million km, that is 116,380 return trips to the Moon; 34,774 rotations of Earth; with the Sun — 691 billion km around the Galactic centre, 26.7 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 291 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 23, 2027; Jupiter — in 2038.
sidereal periods: Mars 686.98 d, Jupiter 11.862 yr - How far the sky has drifted since [EXACT]
The vernal point has shifted 4,788″ 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.