Wider than the diameter of the Earth, this weather phenomenon without equivalent in the solar system could disappear in ten or twenty years.
CENTURIES OF EXISTENCE
Jupiter’s big red spot offers a unique show in the solar system, as the Juno probe has recently shown, approaching it like no gear before it. But maybe more for a very long time! After centuries of existence, it should disappear and “become in the next ten to twenty years a sort of big red circle, “ said Glenn Orton, a planetary scientist at NASA’s Jet Propulsion Laboratory (Pasadena, California), who also participates in the Juno mission.
“Nothing Lasts Forever”
The big red spot is a gigantic crimson anticyclone where the winds blow at more than 700 kilometers per hour. By flying over it at only 9000 kilometers of altitude last July, Juno has shown that it is rooted more than 300 kilometers under the highest clouds of the gas giant and that its diameter is close to 16,000 kilometers or 1.3 times that of the Earth! But the data collected in 1979 by the Voyager 2 probe indicated that its width was twice the diameter of our planet.
And at the end of the XIXth century, the latter was still twice as big! Although some observations suggest that it already existed in the 17th century, the largest and oldest storm of the solar system seems to be gradually absorbed. “Nothing lasts forever, ” says Glen Orton.
In comparison, the most enduring hurricane ever recorded on Earth – named John – lasted only 31 days. In 1994, he swept the Pacific Ocean from east to west before returning to the central regions, traveling more than 13,000 kilometers. If the great red blotch endures for centuries on Jupiter, it is, in particular, because the gaseous giant turns much slower than the Earth and that this anticyclone is wedged between two jet streams very powerful which move in the opposite direction.