While not a real star, the two planets are sure to make a bright splash in the night sky.
“You should go back until the morning of March 4, 1226 to see a closer alignment between these objects visible in the night sky.”
If you’re an astronaut, you’ve probably noticed that Jupiter and Saturn have been approaching since summer. And they are currently visible in our night sky, getting closer and closer to each other.
Between December 16 and 25 they will be even more welcoming. Look for the Jupiter-Saturn conjunction in the western sky for about an hour after sunset every evening during that time.
“You can imagine the solar system being a racetrack, with each of the planets as a corridor in its own lane and the Earth toward the center of the stadium,” said Henry Throop, an astronomer in the Planetary Sciences Division at the headquarters of NASA in Washington.
“From our point of view, we will be able to see Jupiter in the inner lane, approaching Saturn all month and finally overtaking it on December 21.”
How to look
“The night closest to Dec. 21 (cradle) will look like a double planet, separated by only 1/5 of the diameter of the full moon,” Hartigan said. “For most telescope viewers, each planet and several of its largest moons will be visible in the same field of view that night.”
We expect a clear sky because the conjunction will be visible to everyone, with the best perspective for those near the equator.
“The further north there is a spectator, the less time they will have to glimpse the conjunction before the planets sink below the horizon,” Hartigan said.
The planets will be bright enough to be seen at dusk, which may be the best time for many American viewers to observe the conjunction.
“When the sky is completely dark in Houston, for example, the conjunction will be just 9 degrees above the horizon,” Hartigan said. “Seeing this would be manageable if the weather cooperates and you have a clear view to the southwest.”
If you’re in New York or London or along these latitudes, try to locate the conjunction right after sunset. If you wait an hour after sunset, the planets will only get closer to the horizon, which will make them harder to detect.
The best conditions for seeing this astronomical event include a clear southwestern horizon and no low clouds in the distance, Hartigan said. Binoculars or a telescope can help you distinguish the planets. A telescope would allow you to see Saturn’s rings and the brightest moons on both planets, he said.
Jupiter will appear brighter and be easily visible. Saturn will be slightly weaker and will appear slightly above and to the left of Jupiter. On December 21, Jupiter will surpass Saturn and exchange places in our sky.
“On December 21, the sun will set around 4:30. After that, it’s a race; the sky must be dark enough to see Jupiter and Saturn before they set as well, around 6 p.m. : 45, ”said Walter Freeman, assistant professor in the physics department at Syracuse University’s College of Arts and Sciences in New York State.
“Jupiter and Saturn are likely to stand out from the twilight glow from 5:00 or 5:15. With binoculars, a telescope or a 500 (millimeter) telephoto lens focal length or more, you can also see the four largest moons of Jupiter. There is no better way to celebrate the longest night of the year than by watching the stars. So if you’re planning a night of star gazing at the solstice, start admiring the larger planets before they set. “
Live events around the conjunction
If you miss this conjunction and want to see the planets in the same proximity, higher in the sky, it will not happen until March 15, 2080, and not later until 2400.
Between 0 and 3000 CE, or Common Era, only seven conjunctions were or will be closer than this, and two of them were too close to the sun to see them without a telescope, according to Hartigan. So yes, this is an incredibly rare event.
In case the weather conditions in your area are not pleasant to witness this celestial event, several live streams will be available.