Jupiter and Saturn should be visible within the same field-of-view on December 21st whether using binoculars or a small “backyard” telescope along with four of Jupiter’s largest moons spread out in a straight line. Beyond December 21, Jupiter and Saturn will move away from each other rather quickly in terms of appearance to us here on Earth and this trend will continue for the next ten years before they start to converge again during the 2030s. This will set up the next “Great Conjunction” of the year 2040; however, that one will not be as brilliant as this one. In fact, the two planets won’t appear this close again until the year 2080 and in that late 21st century close encounter, Jupiter will completely cover Saturn which is an extremely rare event and won’t happen again until the year 7541.
Make sure to mark your calendars specifically for December 21st to view this once-in-a-lifetime celestial event as this opportunity will be just a one-day affair. Just one day before and one day after, the planets will appear noticeably farther apart from each other and nowhere near as striking as on December 21st – hopefully skies will cooperate on the first day of astronomical winter. The best viewing on December 21st will be from about 30 minutes to an hour after sunset in the low southwestern sky until the time the two planets set (~8:23 PM ET).
Meteorologist Paul Dorian