CAPE CANAVERAL, Florida (AP) – Jupiter and Saturn will unite in the night sky on Monday, appearing closer to each other than they did in Galileo’s time in the 17th century.
Astronomers say so-called conjunctions between the two largest planets in our solar system are not particularly rare. Jupiter passes its neighbor Saturn in respective revolutions around the sun every 20 years.
But the next one is very close: Jupiter and Saturn will be only a tenth of a degree away from our perspective or about a fifth of the width of the full moon. It should be easily visible around the world shortly after sunset, weather permitting.
Throw in the winter solstice in the northern hemisphere, the longest night of the year – and the summer solstice in the southern hemisphere – and this show just in time for Christmas promises to be one of the biggest of the biggest conjunctions.
“The rarest thing is a tight conjunction that appears in our night sky,” said David Weintraub, a professor of astronomy at Vanderbilt University. “I think it’s fair to say that such an event can usually happen only once in anyone’s life, and I think ‘once in my life’ is a pretty good test if something deserves to be labeled as rare or special.”
It will be the closest pair to Jupiter-Saturn in July 1623, when the two planets appeared a little closer. This conjunction was almost impossible to see, however, because of its proximity to the sun.
Considerably closer and more visible was the conjunction of the two planets in March 1226 – when Genghis Khan conquered Asia. The conjunction of Monday will be the closest pair that is visible since then.
Saturn and Jupiter have been approaching the south-southwest sky for weeks. Jupiter – larger and closer to Earth – is much brighter.
“I like to see them getting closer and closer to each other and the fact that I can see them with my naked eyes from the back porch! Virginia Tech astronomer Nahum Arav said in an email.
To see it, be ready shortly after sunset on Monday, looking southwest quite low on the horizon. Saturn will be the smaller and weaker blob in the upper right of Jupiter. Binoculars will be needed to separate the two planets.
Despite appearances, Jupiter and Saturn will actually be more than 730 million kilometers away. Meanwhile, Earth will be 890 million kilometers from Jupiter.
A telescope will not only capture Jupiter and Saturn in the same field of view, but even some of their brightest months.
Their next super-tight pair: March 15, 2080.
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