Jupiter’s Great Red Spot might fade into a great red memory in a few decades, according to planetary scientists.
The Great Red Spot on the largest planet in the solar system is a swirling storm which has been around since the 1600s. NASA’s Juno probe transmitted stunning photos of the storm in July 2017.
In an email to Business Insider, a team member of the Juno mission, Glenn Orton, explained why storms on Jupiter last for a long time.
“They don’t, at least not all of them. Think of the GRS [Great Red Spot] as a spinning wheel that keeps on spinning because it’s caught between two conveyor belts that are moving in opposite directions. The GRS is stable and long-lived, because it’s ‘wedged’ between two jet streams that are moving in opposite directions.”
The jet streams on Jupiter can move at speeds of more than 300 mph, imparting a great force on storms spinning in the opposite direction relative to the rotation of the planet. This is one reason why there is always momentum in the vortex.
The $1 billion Juno spacecraft will take another peek at the Great Red Spot in April this year. The next viewing will be in July and in September 2019, and another flyby in December 2020.
According to Orton, they have no plans to “come as close without changing the orbit from its current configuration.” They will also operate on the presumption that the drift rate of the GRS in Jupiter’s atmosphere remains constant.
Unlike Jupiter, the Earth’s atmosphere does not extend for thousands of miles. Hence, storms on our planet do not last for hundreds of years. The Earth is also smaller in size, and the rotation is slower than Jupiter. The proximity of land and oceans to the atmosphere is also another factor why weather systems and vortexes are more manageable on Earth.
While storms on Jupiter tend to last a long time, they do not last forever. According to him, the Great Red Spot has been shrinking for a long time.
To prove this claim, Orton revealed that during the 1800s, the GRS was about four times the diameter of the Earth or 35,000 miles. However, during Voyager 2’s flyby in 1979, the storm was only twice the Earth’s width.
“Now it’s something like 13 degrees wide in longitude and only 1.3 times the size of the Earth. Nothing lasts forever.”
The storm on Jupiter is not the only one which will end soon. A similar phenomenon has also been observed on Neptune.
As for how long it will be before the Great Red Spot vanishes, Orton had an estimate.
“The GRS will in a decade or two become the GRC (Great Red Circle),” Orton said. “Maybe sometime after that the GRM” — the Great Red Memory.