After sunset on the evening of December 21, 2020, Thursday And Saturn In the night sky of the earth they appear closer together than they were in the Middle Ages, giving the world a celestial feast to sound in the winter solstice.
“Alignments between these two planets are very rare, occurring once every 20 years, but this connection is very rare because of how close the planets appear to each other,” said Rice University astronomer Patrick Hardigan. “On the morning of March 4, 1226, you must return to see a closer alignment between these objects visible in the night sky.”
Jupiter and Saturn have been approaching each other in the earthly sky since summer. From December 16-25, the two will be separated by less than the diameter of a full moon.
“On the evening of the close approach on December 21, they will look like twin planets, separated by only 1/5 of the diameter of the full moon,” said Hardikan, a professor of physics and astronomy. “For most telescopes, each planet and their many large moons are visible at a single glance that evening.”
Although the best viewing conditions are near the equator, this phenomenon is visible anywhere on Earth, weather permitting. Hardigan said the planetary twins appear to be low in the western sky about an hour after sunset each evening.
“An observer is still north, with less time to see the time the planets merge before they sink to the horizon,” he said. Fortunately, the planets are bright enough to be seen at dusk, which may be the best time for many American viewers to notice the merger.
“When the sky is completely dark in Houston, this connection will be 9 degrees above the horizon,” Hardigan said. “The weather will cooperate and manage to see if there is unobstructed view of the southwest.”
But an hour after sunset, people looking up at the sky in New York or London will see the planets even closer to the horizon at 7.5 degrees and 5.3 degrees, respectively. He said it would be good for visitors there, as well as at similar latitudes, to see the rare astronomical sight as soon as possible after sunset.
Those who want to see Jupiter and Saturn together and see the night sky high should stick to March 15, 2080, Hardigan said. After that, the pair will not make such an appearance after 2400.