During the next week Jupiter approaches and passes Saturn for their once-in-a-generation Great Conjunction on December 21, 2020.
On December 15, the razor-thin appears to the lower right of Jupiter and Saturn after sunset. The planets are 0.6° apart.
A little later as the sky darkens further and the moon sets, the planets are visible together low in the southwest.
Just 5 days before the conjunction the crescent moon shines beneath the converging planets. The planet gap is 0.5°, the apparent diameter of the moon in the sky. For the next several evenings, your pinky finger at arms length covers both planets.
December 17, the crescent moon appears to the upper left of the converging planets. The planets are 0.4° apart.
The moon is to the upper left of the planets. The gap between Jupiter and Saturn is 0.3°.
The waxing gibbous moon is to the upper left of the impending conjunction. Bright Jupiter is 0.2° to the lower right of Saturn.
One night before the conjunction, Jupiter is below Saturn.
Jupiter passes Saturn during daylight hours in North America and South America when they share the same celestial longitude – the definition of a conjunction. By nightfall the planets are still close in the southwest after sunset.
Conjunction evening! Jupiter is immediately to the lower left of Saturn.
Through a small telescope or spotting scope, both planets appear in the same field of view. Jupiter’s four largest moons and Saturn’s moons are easy to see.
A binocular may reveal some of the Jovian moons.
The planets are visible as separate “stars” to the unaided eye. They do not merge into a single point or suddenly brighten.
During the next week, watch the Jupiter move away from Saturn.
January 20, 2021: Mercury is low in the west-southwest after sunset. The bright moon is to the lower right of Mars, while the Red Planet passes planet Uranus.
January 19, 2021: Mercury is low in the west-southwest after sunset. The moon is approaching Mars before their grouping tomorrow evening. Mars nears the planet Uranus before tomorrow’s conjunction.
January 18, 2021: Without a bright morning planet, bright Arcturus and the constellation Bootes the Herdsman is high in the south. The crescent moon is in the early evening sky. Mars is near the planet Uranus. They are high in the south-southeast as night falls.