2 large planets of our solar Jupiter and Saturn come closer than they have in centuries, this phenomenon happening at Christmas time so it’s called Christmas Star.
Christmas Star is not actually a star but the 2 planet will make a bright splash in the night sky.
This will happen tonight on 21st December when Jupiter and Saturn will be closely aligned looking like a double planet and this close approach is known as a conjunction.
According to NASA this is occurring during the winter solstice is a coincidence.
Alignments of the 2 planet happens about 20 years however this closer alignment happens last time on March 4, 1226 and this won’t happen until March 15, 2080 and next after 2400