We've known for about 80 years that the Great Red Spot is shrinking, but given the lack of observations, we don't know if this is part of a cycle -- or a permanent downsizing. In 2014, NASA said that perhaps small eddies in the storm could help explain the shrinkage (at least in part). That year, the spot was measured at 10,250 miles across, half of its size as seen in some older measurements. "In our new observations it is apparent very small eddies are feeding into the storm," said Amy Simon, a senior scientist at the NASA Goddard Space Flight Center in Maryland,
in a NASA press release. "We hypothesized these may be responsible for the accelerated change by altering the internal dynamics and energy of the Great Red Spot."
"It's been shrinking longitudinally for over a century now. The GRS may become the GRC (Great Red Circle) and ultimately the GRM (great red memory!)," Glenn Orton, planetary scientist with NASA's Jet Propulsion Laboratory in Pasadena, Calif., wrote in an email to DNews.
Image: Images from NASA's Hubble Space Telescope taken between 1995 and 2014 show the Great Red Spot shrinking. Credit: NASA/JPL/Space Science Institute