♃ Jupiter’s cycles
Jupiter comes back to the same place relative to the Sun about every 399 days, a month longer than a year. It rises out of the Sun’s glare in the dawn sky, and as the Earth comes round to overtake it, it slows, stops and runs backwards for about four months—a retrograde—with opposition in the middle: Jupiter up all night, at its closest and brightest. Then it turns forward again and sinks into the evening twilight to meet the Sun. It takes about twelve years to go once round the zodiac, a sign a year.
Why it runs backward
The retrograde is a trick of perspective—as with Mars, it’s the Earth doing the overtaking. Jupiter is so far out and moves so slowly that we pass it every year, and for four months it seems to slide backwards against the stars.
Around the zodiac
Jupiter comes back to the same part of the sky every 12 years, 4–5° further along.