Jupiter’s Great Red Spot continues to shrink, possibly to its smallest size ever measured
A 2020 Hubble picture of Jupiter.
Click for full image.
Long term data from numerous observatories shows that the Great Red Spot on Jupiter, the largest and longest lasting storm in the solar system, has been continuously shrinking for decades, and appears approaching this year its smallest size ever measured.
Despite so many factors working to keep it “alive” the Spot may be in need of life support. It’s been shrinking for decades. In 2012 the rate of shrinkage abruptly accelerated, something many amateur observers have commented on since that time. Several years later, while still shrinking in diameter, it expanded in latitude becoming more circular. Now it’s narrowed again and continues to diminish in both axes. This observing season I’ve been struck by the Spot’s unusually small size. That, along with its pale pink color and turbulent environment, have made it less obvious than ever.
…Using the WinJUPOS program and one of his recent high-resolution images, Peach measured the Great Red Spot’s diameter on November 6, 2023, at 12,500 kilometers or about 7,770 miles across. If confirmed it would make this season’s GRS not only smaller than the Earth (12,756 kilometers or 7,926 miles across) but the smallest size in observational history. A British Astronomical Association Jupiter section bulletin on October 30th described it as “the smallest it has ever been.” That’s a far cry from the late 1800s when the Spot ballooned to 41,000 kilometers (25,500 miles) — big enough to swallow three Earths with room to spare. Now it can barely contain one!
No one knows if this shrinkage is merely a normal long term fluctuation, or a sign that this many-centuries-old storm is finally dissippating. When it comes to the solar system’s gas giants, their size and long orbits make any firm conclusion difficult in only a few centuries of observation. To understand them properly will likely require thousands of years of observations, covering many orbits and seasons.
A 2020 Hubble picture of Jupiter.
Click for full image.
Long term data from numerous observatories shows that the Great Red Spot on Jupiter, the largest and longest lasting storm in the solar system, has been continuously shrinking for decades, and appears approaching this year its smallest size ever measured.
Despite so many factors working to keep it “alive” the Spot may be in need of life support. It’s been shrinking for decades. In 2012 the rate of shrinkage abruptly accelerated, something many amateur observers have commented on since that time. Several years later, while still shrinking in diameter, it expanded in latitude becoming more circular. Now it’s narrowed again and continues to diminish in both axes. This observing season I’ve been struck by the Spot’s unusually small size. That, along with its pale pink color and turbulent environment, have made it less obvious than ever.
…Using the WinJUPOS program and one of his recent high-resolution images, Peach measured the Great Red Spot’s diameter on November 6, 2023, at 12,500 kilometers or about 7,770 miles across. If confirmed it would make this season’s GRS not only smaller than the Earth (12,756 kilometers or 7,926 miles across) but the smallest size in observational history. A British Astronomical Association Jupiter section bulletin on October 30th described it as “the smallest it has ever been.” That’s a far cry from the late 1800s when the Spot ballooned to 41,000 kilometers (25,500 miles) — big enough to swallow three Earths with room to spare. Now it can barely contain one!
No one knows if this shrinkage is merely a normal long term fluctuation, or a sign that this many-centuries-old storm is finally dissippating. When it comes to the solar system’s gas giants, their size and long orbits make any firm conclusion difficult in only a few centuries of observation. To understand them properly will likely require thousands of years of observations, covering many orbits and seasons.
