Jupiter’s Great Red Spot has been captured at its smallest size to date.
“Recent Hubble Space Telescope observations confirm that the Great Red Spot (GRS) is now approximately 10,250 miles across, the smallest diameter we’ve ever measured,” said Amy Simon of NASA’s Goddard Space Flight Center in Greenbelt, Md. Historic observations as far back as the late 1800s gauged the GRS to be as big as 25,500 miles on its long axis.
Jupiter’s Great Red Spot (GRS) is an atmospheric storm that has been raging in Jupiter’s southern Hemisphere for at least 400 years. The GRS rotates counter-clockwise and makes a full rotation every six Earth days. The speed of winds at the very edges of the storm reaches upto 432 km/h, but inside the storm winds seem to be somewhat stagnant with no inflow nor outflow.
The NASA Voyager 1 and Voyager 2 flybys of Jupiter in 1979 show that it is now 10,250 miles (16,496 kilometers) across, which is less than half the size of the storm in the late 1800s.
The GRS’s “waistline” is strikingly getting smaller by 580 miles per year and the shape change from an oval to a circle has also been observed.
“In our new observations it is apparent that very small eddies are feeding into the storm,” said Simon. “We hypothesized that these may be responsible for the accelerated change by altering the internal dynamics and energy of the Great Red Spot.”
The team Simon now plans to study the motions of the small eddies and also the internal dynamics of the GRS to govern if this eddies can feed or sap momentum entering the upsurge vortex.
The reason behind Jupiter’s most defining feature rapid disappearance is yet to be precisely discovered.
