The Great Conjunction of Jupiter and Saturn
Jupiter and Saturn have been travelling across the sky together this month but right now they are really putting on a show. You can see them in the western sky, very low, each evening for an hour after sunset. A conjunction will occur every 20 years this century but this one is called a “great conjunction”.
On 21st December 2020, the two planets were approximately 1/10 of a degree apart. They will not appear this close in the sky again until the year 2080.
The last time that these two planets were visible across the earth was on 5th March in the year 1226, when they were even closer compared to what we will see this year.
If you have binoculars or a small telescope you will be able to see both Jupiter and Saturn along with Jupiter’s moons.
If you would like to see the moons of Jupiter, train your telescope on Jupiter that night, and if there are no clouds, three of the four famous Galilean satellites will be visible. The moons of Jupiter that will be visible are Callisto, Io and Europa.
On one side of Jupiter, you’ll see its volcanic moon, Io (closest to Jupiter’s disk) and second-largest moon, Callisto. On the other side of Jupiter will be Ganymede, Jupiter’s largest moon. As for Europa, it will be in transit, crossing in front of Jupiter, so cannot be seen.
This could be a “once in a lifetime opportunity” to see the Great Conjunction of the planets Saturn and Jupiter. The planets will be visible until the end of January 2021.
In this photo, taken with a cell phone in Australia, the two planets can be clearly seen