On Monday, Jupiter and Saturn will look as if they are merging in the night sky. This hasn't happened in nearly 400 years.
LULU GARCIA-NAVARRO, HOST:
A cosmic kiss, a celestial celebration, a rare heavenly happening will light up the skies this Monday night, December 21. It's not the solstice. That's just for the sun. This is being called the great conjunction, a once-in-a-lifetime chance to see the distant planets Jupiter and Saturn appear to touch. Both planets will move within a tenth of a degree apart in the night sky. That has backyard stargazers and real astronomers excited.
HENRY THROOP: So this is really neat that you can see the planets from essentially everywhere.
GARCIA-NAVARRO: That's planetary scientist Dr. Henry Throop of NASA, whose enthusiasm is contagious. He says Jupiter and Saturn won't necessarily be brighter, but they'll look that way because of their proximity to each other, something they've been working toward all month.
THROOP: What is going to be unique here is how close Jupiter and Saturn are to each other. They will look the same, but they're going to be inching closer and closer and closer to each other in the sky.
GARCIA-NAVARRO: Throop says you won't even need to go somewhere dark to see this. The two planets will be visible from the most brightly lit cities on Earth without the need for binoculars or a telescope. So if you want to plan your backyard space odyssey, Throop has some tips.
THROOP: If you can see the sunset, then you'll be able to see Saturn and Jupiter. You want to go outside about maybe 45 minutes after sunset and then look toward the sunset. And you'll have about an hour of time where you can observe Jupiter and Saturn in the sky. What they'll look like is very bright stars. Jupiter will look like the brightest star in the sky. Of course, it's not a star. It's Jupiter. It's reflecting all of its light. And then Saturn is going to be a little bit above, a little bit to the left of Jupiter and a little bit fainter.
GARCIA-NAVARRO: This evening apparition actually takes place every 20 years or so, but it hasn't been this close or this bright since 1623, just a decade or so after Galileo himself first observed and sketched the moons of Jupiter. Something lovely finally in 2020, a cosmic gift from the heavens.
(SOUNDBITE OF BERLINER PHILHARMONIKER AND HERBERT VON KARAJAN'S "JUPITER, THE BRINGER OF JOLLITY") Transcript provided by NPR, Copyright NPR.