On the night of the winter solstice, Jupiter and Saturn will appear so closely aligned in our sky
The two largest planets in our solar system, Jupiter and Saturn, will come closer today. It is a very exciting event, as they have never come so close in hundreds of years. This is happening just in time for Christmas, hence the nickname of the “Christmas Star.
Jupiter and Saturn will come closer: the “Christmas Star”
On the night of December 21, the winter solstice, Jupiter and Saturn will appear so closely aligned in our sky. This close approach is called “conjunction”.
While conjunctions are not rare, this one represents a very great event. About this, Patrick Hartigan, a professor of physics and astronomy at Rice University in Houston, said in a statement: “Alignments between these two planets are rather rare, occurring once every 20 years or so, but this conjunction is exceptionally rare because of how close the planets will appear to one another.”
So, the two biggest planets in the solar system will be just 0.1 degrees apart and they will appear together as the brightest object in the sky. Morevover, Professor Michael Burton, an astronomer of Armagh Planetarium and Observatory in Northern Ireland, said a conjunction represents one possibility for what has become known as the Christmas Star from the story of Jesus’ birth. More in detail, he said: “The whole question of what might the Christmas star have been is a very interesting question in its own right. Whether it was a conjunction, whether it was a comet, whether it was a supernova. No-one actually knows what it was.”
How to watch the event
If you are a stargazer, the best advice is to look to the south west as soon as possible after sunset. In particular, the best time will be between 4.30pm and 6pm.
A telescope or binoculars will help you to see better the phenomenon. However, it will be also to the naked eye, weather permitting.
About this, The Royal Astronomical Society encouraged people to find a line of sight without tall buildings or trees. In this way, they will be able to see the event without hindrance.
Moreover, the society clarified: “With the eye, the pair of planets will appear as two bright points of light. Binoculars will show those points as slightly larger dots: viewers may also be able to make out the four largest moons of Jupiter, and possibly Saturn’s largest moon Titan”. At the same time, it said: “With a small telescope the two planets will be in the same field of view, an exceptionally rare event, and the cloud belts on Jupiter and the rings of Saturn should be obvious.”