Jupiter and Saturn, the two largest planets in the solar system, will be stationed in nearly the same spot in the night sky on Monday, creating a bright spectacle.
According to NASA, the positions of the two planets align once every 20 years. While conjunctions occur several times over the course of a typical lifetime, a conjunction of this magnitude is quite rare. The last time the two planets were so close to each other in the night sky was 400 years ago, but no one could see it since that conjunction took place during the day.
The last time a conjunction of its magnitude occurred at night was 800 years ago.
The best time to see the conjunction is about an hour after sunset in the southwestern sky. Jupiter will appear brighter than Saturn because it is closer and bigger.
So what causes the conjunction?
“You can imagine that the solar system is a racetrack, with each of the planets like a runner in its own orbit and the Earth toward the center of the stadium,” said Henry Throop, astronomer with the Planetary Science Division on the planet. NASA headquarters in Washington. . “From our vantage point, we can see Jupiter on the inner orbit, approach Saturn for the entire month and finally catch up on December 21.”
The timing of the conjunction adds to the spectacle. Monday also marks the winter solstice.
As it is four days before Christmas, some call the event “The Christmas Star,” although the conjunction is of planets and not stars. Scientists have long speculated whether the star of Bethlehem was the 7 BC. Conjunction of the two planets was.
“Conjunctions like these can happen on any day of the year, depending on where the planets are in their orbits,” Throop said. The date of the conjunction is determined by the positions of Jupiter, Saturn and the Earth in their orbits around the sun, while the date of the solstice is determined by the tilt of the Earth’s axis. The solstice is the longest night of the year, so this rare coincidence will give people a great opportunity to get out and see the solar system. “
Although the two planets will appear to be very close to each other, in reality they will be hundreds of millions of miles apart.