When you think of Jupiter I bet the first image that comes to mind is the “Great red spot”, which is actually a giant anti-cyclonic storm that could fit almost 3 Earths inside it but there’s a problem, it’s shrinking!
The great red spot was first discovered by Giovanni Domenico Cassini in the 1600s and was first definitively observed with a telescope by Samuel Heinrich Schwabe in 1831. It has since been closely watched by astronomers using Earth telescopes, Voyagers 1 and 2 and the Hubble Telescope, which provided the latest pictures of the spot’s shrinkage.
Using the early photos, descriptions and drawings from Schwabe and others, the oval-shaped Great Red Spot was estimated to be 41,000 km’s in length in the late 1800s. It was first observed to be getting smaller in the 1930s and The Voyager 1 and Voyager 2 flybys in 1979 measured it at 23,335 km’s across. The most recent photographs taken by the Hubble telescope put its current size at 16,496 km’s and its shape is now almost circular instead of oval.
So how fast is the spot shrinking? Based on historical and current data Jupiter’s great red spot is shrinking by 933 km’s per year and based off this the red spot will cease to exist in 15 to 20 years if trends continue.
So what’s causing the Great Red Spot to shrink? Dr Amy Simon of NASA’s Goddard Space Flight Centre has a theory.
“In our new observations, it is apparent that very small eddies are feeding into the storm. We hypothesized that these may be responsible for the sudden change by altering the internal dynamics and energy of the Great Red Spot”
NASA and other agencies will continue to monitor the great red spot to try and determine why it has shrunk and hopefully this icon of our solar system will recover as a future without it sounds horrible.
Stay Curious – C.Costigan
