Jupiter and Saturn are set to align in the night sky for the first time 800 years on December 21st.
The planets will appear so close that they will look like a bright double point of light in the sky for the first time since 1623.
The planets will form a double planet and will look like a Christmas star.
However, in reality the planets will actually be the same distance the Earth is from the sun.
Patrick Hartigan, astronomer at Rice University. said: “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 be to one another.”
How can I see it?
The impressive alignment will take place in the western sky on December 21st for around an hour after sunset.
Look above the southwestern horizon on 21 December after sunset, at around 5pm.
All you need is an unobstructed view to the southwest, a clear patch of sky, and to look to the southwest from about 45 minutes after sunset where you are.
If you miss it you will have to wait until 2080 to see it again and if you miss that one you will only have to wait another 400 years when it will happen again in 2400.
The best chances of spotting the alignment will be on Sunday night as skies are set to be cloudy on Monday evening.