How to see Jupiter and Saturn’s great conjunction

Starwatch graphic

The moment has arrived. Keep your fingers crossed for clear skies tonight and whatever else you are doing, make the attempt to see the extraordinary conjunction of Jupiter and Saturn.

Known as a grand conjunction, the line of sight to each planet is now lying so close to one another that you will probably not be able to distinguish them as separate objects. Find somewhere with a clear south-western horizon and look for the brightest thing you can see, low in the twilight sky: that object will be both Jupiter and Saturn.

The chart shows the view looking south-west from London on 21 December at 1700 GMT. Don’t be late, the planets will set early this evening.

The last time the planets were this close from our viewpoint on Earth was almost 400 hundred years ago on 16 July 1623. Of course, the planets aren’t really close together, Jupiter is currently 886,440km from Earth and Saturn is another 733,205km beyond it. They happen to lie in the same direction. The conjunction is visible from most parts of the planet.