Starting at sunset on the evening of December 21, 2020, Jupiter and Saturn will appear close to each other in Earth’s night sky since the Middle Ages.
“The link between these two planets is quite rare, occurs once every 20 years, but this combination is all the more rare as the planets appear closer together than imagined. To see a similar event, you will have to go back there just before dawn on March 4, 1226, to see a closer connection between the two planets, ”the researchers said.
This combination is especially rare for planets to appear closer than expected.
From December 16 to 25, the two will be separated by less than the diameter of the Moon.
“On the evening of their last approach, December 21, they would look like a double planet, only one-fifth the diameter of the full moon. For most viewers, each of the planets and some of their larger moons will be seen in the same field of view later in the evening, ”said Hartigan, professor of physics and astronomy.
Although the best viewing conditions are near the equator, the event can still be observed anywhere on Earth, depending on the weather.
Hartigan said the planetary duo will appear low in the western sky for about an hour after sunset.
“The farther north the viewer is, the less time they will have to see the combination before the planets descend below the horizon. Fortunately, the planets will be bright enough to be seen at sunset, which may be the best time for many people in America, ”Hartigan said.
By the time the sky is completely dark over Houston, the suit will only be 9 degrees above the horizon. This observation would be controllable if the weather conditions were favorable and the visibility was clear to the southwest.
But an hour after sunset, people looking at the sky in New York or London will see the planets even closer to the horizon, around 7.5 degrees and 5.3 degrees, respectively. Viewers there and at similar latitudes, it would be great to be able to see the rare astronomical spectacle after sunset.
Those who like to wait to see Jupiter and Saturn close together and higher in the night sky will have to follow until March 15, 2080, Hartigan adds. so until approximately after 2400.