The sky on December 21, 1928 — as it really was
That day the Sun stood in Sagittarius — sign and constellation agree here.
Bodies on the ecliptic (noon UTC)
- ☉︎ Sun — 269.4° · sign Sagittarius · constellation Sagittarius
- ☽︎ Moon — 16.3° · sign Aries · constellation Pisces
- ☿︎ Mercury — 271.1° · sign Capricorn · constellation Sagittarius
- ♀︎ Venus — 311.3° · sign Aquarius · constellation Capricornus
- ♂︎ Mars — 89.5° · sign Gemini · constellation Gemini
- ♃︎ Jupiter — 30.5° · sign Taurus · constellation Aries
- ♄︎ Saturn — 262.5° · sign Sagittarius · constellation Ophiuchus
- ☽︎ Moon 65% 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, 65% lit; the Moon was 373,872 km away.
astronomy-engine - How far Earth has travelled since [EXACT]
97.8 orbits of the Sun — 91,897 million km, that is 119,533 return trips to the Moon; 35,716 rotations of Earth; with the Sun — 709.8 billion km around the Galactic centre, 27.4 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 88 million km away; today it is 245 million km (farther by 2.8×).
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 October 11, 2026; Jupiter — in 2035; a full moon exactly on this date — December 20, 2029
sidereal periods: Mars 686.98 d, Jupiter 11.862 yr - How far the sky has drifted since [EXACT]
The vernal point has shifted 4,896″ 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.