A conjuntion of planets occurs when
the two planets are aligned along their orbits in relation to the
Earth. A conjuntion between Jupiter and Saturn occurs every 20 years
but they have not appeared this close to each other (.1 degree apart)
since 1623. However, at that time, they were too close to the sun
to be seen with the naked eye. The last time this was clearly visible
was in 1226. They will not appear as close to each other again until
March of 2080.
This event has been refered to as
the "Christmas Star" due to its timing. The planets were
at their closest on the winter soltace (12/21/2020). This particular
image was not taken until Chritmas Eve.