Later this month, look up to see Jupiter and Saturn appear closer together than they've been since the Middle Ages

On Monday night, December 21, Jupiter and Saturn will look closer together than they've appeared since March 4, 1226, almost 800 years ago. This event, taking place on the December solstice, is known as a "great conjunction."

"On the evening of closest approach on Dec 21 they will look like a double planet, separated by only 1/5th the diameter of the full moon," says Rice University astronomy professor Patrick Hartigan.

From Rice University:

Though the best viewing conditions will be near the equator, the event will be observable anywhere on Earth, weather-permitting. Hartigan said the planetary duo will appear low in the western sky for about an hour after sunset each evening[…]

Those who prefer to wait and see Jupiter and Saturn this close together and higher in the night sky will need to stick around until March 15, 2080, Hartigan said. After that, the pair won't make such an appearance until sometime after the year 2400.

Learn more in the NASA-Jet Propulsion Laboratory's December 2020 Skywatching Tips: