Sky on December 17, 1977: where the Sun, Moon and planets really were

The real sky on December 17, 1977: Sun in Ophiuchus (horoscope says "Sagittarius"), Moon 51% lit, planet positions from ephemerides.

The sky on December 17, 1977 — as it really was

That day the Sun stood in Ophiuchus, while the horoscope says "Sagittarius". The gap is 23.6° of precession.

astronomy-engine ephemerides (VSOP87/ELP), IAU 1930 constellation boundaries. Positions accurate to a fraction of a degree.

Checkable facts with a tag and a source; the classical reading is in the chart.

The Moon that day [EXACT]
first quarter, 51% lit; the Moon was 385,561 km away.
astronomy-engine
How far Earth has travelled since [EXACT]
48.8 orbits of the Sun — 45,864 million km, that is 59,656 return trips to the Moon; 17,825 rotations of Earth; with the Sun — 354.2 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 113 million km away; today it is 243 million km (farther by 2.1×).
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 11, 2026; Jupiter — in 2036; a full moon exactly on this date — December 16, 2032
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

Computed from the date only; nothing about you is stored.