All eyes are on the sky this month. As most of us probably know by now, Jupiter and Saturn come together and form their every-two-decades conjunction on December 21. And this time they really come together – they stand only one-tenth of a degree apart. That’s close! They won’t “blend into one star” as some people have erroneously said – you will still see two points of light. But it will be a striking sight, something you may have never before seen in the sky.How close is one-tenth of a degree? Here’s a way to visualize it in advance before you can actually see the real thing. Hold your arm straight out and stand your pinky-finger straight up. The span across your fingernail is about one degree.
Hey, but what if it’s cloudy on the night of the 21st? Have you missed the whole thing? Do you have to wait another twenty years? Well . . . it’s both worse than that and better than that. The next Jupiter-Saturn conjunction occurs in October of 2040, but it’s a just pale version of this one – the two planets are much further apart (because of declination) and somewhat lost in the Sun’s glare. Twenty years after that one, they are at it again – but once more, conditions are similar to 2040.
One tenth of that. Close!