The sky on December 21, 1977 — as it really was
That day the Sun stood in Sagittarius — sign and constellation agree here.
Bodies on the ecliptic (noon UTC)
- ☉︎ Sun — 269.5° · sign Sagittarius · constellation Sagittarius
- ☽︎ Moon — 45.6° · sign Taurus · constellation Aries
- ☿︎ Mercury — 269.7° · sign Sagittarius · constellation Sagittarius
- ♀︎ Venus — 261.9° · sign Sagittarius · constellation Ophiuchus
- ♂︎ Mars — 131.0° · sign Leo · constellation Cancer
- ♃︎ Jupiter — 91.3° · sign Cancer · constellation Gemini
- ♄︎ Saturn — 150.5° · sign Virgo · constellation Leo
- ☽︎ Moon 86% 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 gibbous, 86% lit; the Moon was 402,438 km away.
astronomy-engine - How far Earth has travelled since [EXACT]
48.8 orbits of the Sun — 45,848 million km, that is 59,636 return trips to the Moon; 17,819 rotations of Earth; with the Sun — 354.1 billion km around the Galactic centre, 13.7 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 110 million km away; today it is 245 million km (farther by 2.2×).
astronomy-engine; checked against JPL Horizons for 2026-09-14 - Solar cycle [ESTIMATE]
That day fell in solar cycle 21, right at the minimum (17% through the cycle).
SILSO smoothed minima - When the sky repeats [EXACT]
Mars returns to that day’s point of its orbit on November 15, 2026; Jupiter — in 2036; 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 2,448″ since that day; the real constellations now sit 23.6° away from the astrologers’ “signs”.
precession 50.29″/yr
Other dates
Computed from the date only; nothing about you is stored.