Jupiter and Saturn will come together in the night’s sky later this month, forming what will appear to be a single bright star above the horizon - and some have likened the merging of the two gas giants to the Christmas Star.
The event, known as the “Great Conjunction”, will take place on the longest night of the year, offering stargazers a unique opportunity to view it. The winter solstice, which occurs on 21 December, will also coincide with the peak of the Ursid meteor shower, marking a spectacular end to the astronomical calendar in 2020.
This month’s Great Conjunction will be the closest encounter of the two largest planets in the solar system since 1623, despite Jupiter and Saturn passing close to each other every 20 years or so. The planets will once again conjoin within one tenth of a degree of each other in 2080, meaning this may be the last chance for many people to see such a conjunction within their lifetimes.
Jupiter and Saturn will come within 0.1 degree of each other – around one fifth of the moon’s diameter – and it will be visible from all around the world. Weather permitting, the two planets will briefly appear as a single entity to the naked eye, just above the horizon when looking southwest shortly after sunset.
Each night leading up until 21 December, Jupiter and Saturn will “gradually move closer to each other”, according to NASA. “Keep in mind that while the two gas giants may appear close, in reality they are hundreds of millions of miles apart,” the US space agency said. “This will be quite a striking sight, but you will need to look fast as both planets will set shortly after sunset.”