Tonight, Saturn and Jupiter will move closer than they’ve ever been since the 1600s. They will overlap briefly in the sky tonight- forming the appearance of a “double star.”
Samir Salim is an assistant professor in Indiana University’s astronomy department. He says a Jupiter-Saturn conjunction happens every 20 years, but this year’s will be exceptional given how close they will be together.
“It’s like a race of two cars and one car is kind of overtaking the other car," he says. "The car that is overtaking the other is Jupiter. Saturn is slower. Jupiter is slightly faster and it’s catching up and now it’s about to overtake it.”
The best time to spot the conjunction in the southwest of the horizon is about an hour after sunset.
Salim says if it’s cloudy, the conjunction may not be visible. But he adds the planets will be close to each other for days after, so even if you aren’t able to catch the conjunction, you can spot the two largest planets shiny brightly close to each other.
He says it’s just a coincidence that the conjunction is taking place on Winter Solstice.
