The sky on December 20, 1990 — as it really was
That day the Sun stood in Sagittarius — sign and constellation agree here.
Bodies on the ecliptic (noon UTC)
- ☉︎ Sun — 268.3° · sign Sagittarius · constellation Sagittarius
- ☽︎ Moon — 304.5° · sign Aquarius · constellation Capricornus
- ☿︎ Mercury — 277.0° · sign Capricorn · constellation Sagittarius
- ♀︎ Venus — 280.3° · sign Capricorn · constellation Sagittarius
- ♂︎ Mars — 58.7° · sign Taurus · constellation Taurus
- ♃︎ Jupiter — 132.9° · sign Leo · constellation Cancer
- ♄︎ Saturn — 294.4° · sign Capricorn · constellation Sagittarius
- ☽︎ Moon 10% 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, 10% lit; the Moon was 400,618 km away.
astronomy-engine - How far Earth has travelled since [EXACT]
35.8 orbits of the Sun — 33,637 million km, that is 43,752 return trips to the Moon; 13,073 rotations of Earth; with the Sun — 259.8 billion km around the Galactic centre, 10 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 90 million km away; today it is 244 million km (farther by 2.7×).
astronomy-engine; checked against JPL Horizons for 2026-09-14 - Solar cycle [ESTIMATE]
That day fell in solar cycle 22, on the rise to maximum (43% through the cycle).
SILSO smoothed minima - When the sky repeats [EXACT]
Mars returns to that day’s point of its orbit on August 2, 2028; Jupiter — in 2037; a full moon exactly on this date — December 20, 2048
sidereal periods: Mars 686.98 d, Jupiter 11.862 yr - How far the sky has drifted since [EXACT]
The vernal point has shifted 1,800″ 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.