Researchers have published a study in Nature Astronomy showing a never-before-seen jet stream on Jupiter’s equator, and scientists have more questions than answers.
“This is something that totally surprised us,” said Ricardo Hueso of the University of the Basque Country in Bilbao, Spain, lead author on the paper.
“What we have always seen as blurred hazes in Jupiter’s atmosphere now appear as crisp features that we can track along with the planet’s fast rotation.”
The research team analysed data captured in July 2022 from JWST Near-Infrared Camera (NIRCam), finding a high-speed jet stream, which spans more than 4,800 kilometres wide and sits over Jupiter’s equator above the main cloud decks.
Researchers also noted a number of wind shears – areas where wind speeds change with height or distance – which enabled them to track the jet.
“We knew the different wavelengths of Webb and Hubble would reveal the three-dimensional structure of storm clouds, but we were also able to use the timing of the data to see how rapidly storms develop,” said University of California, Berkeley’s Michael Wong, who led the associated Hubble observations.
They found the jet is travelling at 515 km per hour and is located in Jupiter’s lower stratosphere, just above the tropospheric hazes, next to the boundary between the troposphere and stratosphere layers.
The jet has given researchers more insight into how the layers of Jupiter’s famously turbulent atmosphere interact with each other, although there’s still plenty more to discover.
“Jupiter has a complicated but repeatable pattern of winds and temperatures in its equatorial stratosphere, high above the winds in the clouds and hazes measured at these wavelengths,” says Leigh Fletcher from the University of Leicester in the United Kingdom.
“If the strength of this new jet is connected to this oscillating stratospheric pattern, we might expect the jet to vary considerably over the next 2 to 4 years – it’ll be really exciting to test this theory in the years to come.”