Jupiter and Saturn, have fascinated astronomers for hundreds of years. But the two gas giants will do something next month not seen since the Middle Ages -- they will look like a double planet.The rare occurrence will happen after sunset on Dec.
21, 2020, the start of the winter solstice.“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,” said Rice University astronomer Patrick Hartigan in a statement. “You’d have to go all the way back to just before dawn on March 4, 1226, to see a closer alignment between these objects visible in the night sky.”Between Dec.