An unusual meeting is expected to take place in the sky on Monday: Jupiter and Saturn, the two largest planets in the solar system, will get as close as possible during a “great conjugation” that won’t happen again until 2080.
After sunset, at 7:22 pm (Swiss time), two gas giants will appear in the same field of view to an observation device, giving the impression of brushing against each other when they are actually located several hundred millions of kilometers. away.
To enjoy the show, you will need to bring a small observation device, find a very clear sky, and look to the southwest, covering western Europe and a large part. Of Africa.
Illusion of a single star
The apparent coherence between the two planets has already begun for several months, and will reach a minimum distance on the winter solstice (a coincidence of the calendar), which will almost give the impression of what two stars do in the sky? One.
“The Great Consulation” corresponds to the time it takes for two planets to find the same relative location of the Earth, explains Florent Delefley of the Paris Observatory – PSL.
Every 20 years
Jupiter, the largest, the Sun in 12 years, orbits Saturn in 29 years. And every 20 years, when we observe the celestial vault from the Earth, both planets appear to grow closer. With the effect of a perspective, the two giants will again appear side-by-side, “with a gap of only 6 arc minutes between them, which corresponds to about 1 / 5th of the moon’s apparent diameter”, continues Florent Delefée.
“With a small observation device, even a simple pair of binoculars can see the equatorial band of Jupiter and its main satellites in the same region, as well as the rings of Saturn,” the astronomer rejoices. To the naked eye, a dual planet will give the impression, “Jupiter and Saturn are two very bright stars,” he explains.
afp / jpr