Great conjunction Jupiter Saturn: what will happen in the sky Monday evening? LIGHTING - This Monday, December 21, at 7:22 p.m.

Jupiter and Saturn, the two largest planets in the solar system, will get as close as possible, giving the impression that they are brushing against each other.

If the conditions are optimal, you will be able to observe an unusual spectacle in the sky this Monday evening at 19:22. Jupiter and Saturn will get as close as possible during a "Great conjunction" , thus giving the impression that they brush against each other for about ten minutes. This event, in the same proportions, will not be repeated until 2080.

The two largest planets in  the solar system  will approach after sunset, at 7:22 p.m. in France. These two gas giants will appear in the same field of view of an observational instrument , making it appear as though they are brushing against each other when in reality they are several hundred million kilometers away from each other. other.

In order to attend this meeting, you will need to bring an observation instrument, find a very clear sky and look towards the South-West , over a strip of territory encompassing Western Europe ( Ireland, Great Britain, France, Spain, Portugal) and a large part of Africa.

Last Great conjunction so close in 1963

If the rapprochement between  Saturn  and Jupiter began several months ago, it will reach a minimum distance on the day of the winter solstice , which will almost give the impression that the two planets are one.

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"The Great conjunction" corresponds "to the time it takes for the two planets to find similar relative positions with respect to the Earth ", explains Florent Deleflie, of the Paris Observatory - PSL. Jupiter , which is the largest in the solar system, circles the Sun in 12 years. Saturn in 29 years. About every 20 years, the two seem to become one when looking at the sky from Earth.

By a perspective effect, the two giants will then appear side by side , "with a gap of only 6 arc minutes between them , which corresponds to approximately 1 / 5th of the apparent diameter of the Moon", specifies Florent Deleflie. "With a small observation instrument, even a simple pair of binoculars, we can see in the same field the equatorial bands of Jupiter and its main satellites, as well as the rings of Saturn ", rejoices the astronomer.

"Jupiter and Saturn being two very luminous stars", their coming together seen with the naked eye will give the impression of a double planet. The last time a Great Conjunction occurred was in 2000 , however, you have to go back to 1623 to find a gap as small as that of Monday. And before finding such a close conjunction, we will have to wait until March 15, 2080.

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