Jupiter's Great Red Spot: New Study Finds It's Getting Taller
Good news for Jupiter’s Great Red Spot: the planet’s most recognizable storm might not be shrinking as consistently as scientists once thought.
The Great Red Spot was once big enough to swallow three Earths but has seen a downward spiral for the greater part of the last 150 years. A new study from NASA confirms that the storm is roughly a third of its former size and is only “big enough to accommodate just over one Earth at this point,” which is not nearly as intimidating.
Yet, this new study, published in The Astronomical Journal, reveals that the Great Red Spot did increase at least once since 1878, and is even growing taller as it gets thinner, making it more of a lanky red spot. Scientists who have observed the storm’s dwindling size were shocked to see the Great Red Spot develop into a narrower shape.
“Storms are dynamic, and that’s what we see with the Great Red Spot. It’s constantly changing in size and shape, and its winds shift, as well,” said Amy Simon, lead author on the study and planetary atmospheres expert at NASA’s Goddard Space Flight Center.
To find this shift, Simon and her colleagues dove deep into the archives on Jupiter, combining them with annual observations from NASA’s Hubble Space Telescope and data from the two Voyager missions in 1979. By merging all of this data, the team was able to trace the evolution of the Great Red Spot not just in size and shape, but in drift rate.
Their findings suggest that the Great Red Spot is drifting westward at a faster rate than before. The storm has kept the same latitude thanks to jet streams in the north and south holding it in place. Historically, the storm has drifted westward against the planet’s eastward rotation at a slow and steady pace. But now, it’s picking up speed.
Usually as storms contract, internal winds become even stronger by picking up speed, as well. However, instead of spinning faster, the storm appears to be stretching upward. NASA’s report compared this to clay being shaped on a potter’s wheel, where the artist turns a wide, round lump into a tall structure by pushing inward.
Jupiter, that “creamy latte” in the sky, isn’t lacking in scientific anomalies. New studies published earlier in March suggest that the planet’s polar regions are harboring cyclones while its moon Europa is appearing more and more Earth-like to observers.
Simon’s findings in the new study also confirmed that the Great Red Spot did grow in size in the 1920s, breaking up the downward trend at least momentarily. While smaller in size, a taller and faster-moving Great Red Spot proved it still has many mysteries to offer.