NASA’s Juno spacecraft spied the new Jovian cyclone on November 3, 2019, during its 23rd science pass of the gas giant.
Juno launched on August 5, 2011, with the ambitious mission of finally seeing beneath the dense clouds covering Jupiter. On July 4, 2016, the probe finally reached the giant planet’s orbit.
Soon after the arrival, Juno’s cameras discovered giant cyclones encircling the Jovian poles — nine in the north and six in the south.
With each flyby, the data reinforced the idea that five windstorms were swirling in a pentagonal pattern around a central storm at the south pole and that the system seemed stable. None of the six storms showed signs of yielding to allow other cyclones to join in.
“Data from Juno’s Jovian Infrared Auroral Mapper (JIRAM) instrument indicates we went from a pentagon of cyclones surrounding one at the center to a hexagonal arrangement,” said Juno team member Dr. Alessandro Mura, a researcher with the National Institute for Astrophysics in Rome, Italy.
“This new addition is smaller in stature than its six more established cyclonic brothers.”
“It’s about the size of Texas. Maybe the JIRAM data from future flybys will show the cyclone growing to the same size as its neighbors.”
The new data from the JIRAM instrument indicate wind speeds of the cyclone average 362 kmh (225 mph) — comparable to the velocity found in its six more established polar colleagues.
The probe’s JunoCam obtained visible-light imagery of the newfound cyclone.
“The two datasets shed light on atmospheric processes of not just Jupiter but also fellow gas giants Saturn, Uranus and Neptune as well as those of giant exoplanets now being discovered,” the researchers said.
“They even shed light on atmospheric processes of Earth’s cyclones.”
“These cyclones are new weather phenomena that have not been seen or predicted before,” said Juno scientist Dr. Cheng Li, from the University of California, Berkeley.
“Nature is revealing new physics regarding fluid motions and how giant planet atmospheres work.”
“We are beginning to grasp it through observations and computer simulations.”
“Future Juno flybys will help us further refine our understanding by revealing how the cyclones evolve over time.”