The two largest planets in the solar system, Jupiter and Saturn, are so closely passing each other on December 21 that they seem to form "double planet", also called a ‘poinsettia’ by astronomers.
Most recently, this phenomenon, known as the planetary combination, was clearly visible from Earth in 1226.
In Finland, the combination is best seen in the south of Oulu early in the evening, at about 4 pm. and look southwest, according to NASA.
The planets are set on a very low horizon, and therefore buildings and trees can easily obscure the view, and are likely to appear as a single point of light to the naked eye. However, the combination is more easily distinguished by binoculars or a telescope, including the rings of Saturn and the four largest moons of Jupiter: Io, Europa, Ganymede, and Callisto.
Proof of connection also depends on weather conditions, especially clear skies.
A similar “close encounter” occurred about 400 years ago, in 1623, but the planets were too close to the sun at the time and therefore very difficult to see from Earth.
Although the planets appear close, in reality they are millions of miles apart. Jupiter’s average distance from the sun is 779 million kilometers, while Saturn is about 1.4 billion kilometers.
Source: The Nordic Page