As 2020 comes to a close, a once-in-a-lifetime sight will be up the night sky.
It's called the "Great Conjunction" (the moment when Jupiter and Saturn appear close together).
It will happen on December 21, which also marks the Winter Solstice.
This is the first Jupiter-Saturn conjunction since 2000, but the first time in nearly 800 years the planets have been this close. According to Chicago's Adler Planetarium, they'll be "a tenth of a degree apart."