The sky on September 21, 1984 — as it really was
That day the Sun stood in Virgo — sign and constellation agree here.
Bodies on the ecliptic (noon UTC)
- ☉︎ Sun — 178.7° · sign Virgo · constellation Virgo
- ☽︎ Moon — 127.8° · sign Leo · constellation Cancer
- ☿︎ Mercury — 163.6° · sign Virgo · constellation Leo
- ♀︎ Venus — 204.9° · sign Libra · constellation Virgo
- ♂︎ Mars — 260.7° · sign Sagittarius · constellation Ophiuchus
- ♃︎ Jupiter — 273.9° · sign Capricorn · constellation Sagittarius
- ♄︎ Saturn — 223.4° · sign Scorpio · constellation Libra
- ☽︎ Moon 19% 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]
waning crescent, 19% lit; the Moon was 368,440 km away.
astronomy-engine - How far Earth has travelled since [EXACT]
42 orbits of the Sun — 39,504 million km, that is 51,384 return trips to the Moon; 15,353 rotations of Earth; with the Sun — 305.1 billion km around the Galactic centre, 11.8 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 168 million km away; today it is 245 million km (farther by 1.5×).
astronomy-engine; checked against JPL Horizons for 2026-09-14 - Solar cycle [ESTIMATE]
That day fell in solar cycle 21, on the decline (82% through the cycle).
SILSO smoothed minima - When the sky repeats [EXACT]
Mars returns to that day’s point of its orbit on December 26, 2027; Jupiter — in 2031; 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 2,088″ since that day; the real constellations now sit 23.7° away from the astrologers’ “signs”.
precession 50.29″/yr
Other dates
Computed from the date only; nothing about you is stored.