The newly-discovered intense (140 m/s) jet is confined to ±3° of Jupiter’s equator, is approximately 4,800 km wide, and is located in the gas giant’s lower stratosphere, according to a paper published in the journal Nature Astronomy.
“This is something that totally surprised us,” said Dr. Ricardo Hueso, an astronomer at the University of the Basque Country.
“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.”
In the study, Dr. Hueso and colleagues analyzed data gathered by Webb’s Near-Infrared Camera (NIRCam) instrument in July 2022.
“Even though various ground-based telescopes, spacecraft like NASA’s Juno and Cassini, and the NASA/ESA Hubble Space Telescope have observed the Jovian system’s changing weather patterns, Webb has already provided new findings on Jupiter’s rings, satellites, and its atmosphere,” said Professor Imke de Pater, an astronomer at the University of California, Berkeley.
“While Jupiter is different from Earth in many ways — Jupiter is a gas giant, Earth is a rocky, temperate world — both planets have layered atmospheres.”
“Infrared, visible, radio, and ultraviolet-light wavelengths observed by these other missions detect the lower, deeper layers of the planet’s atmosphere — where gigantic storms and ammonia ice clouds reside.”
“On the other hand, Webb’s look farther into the near-infrared than before is sensitive to the higher-altitude layers of the atmosphere, around 25-50 km above Jupiter’s cloud tops.”
“In near-infrared imaging, high-altitude hazes typically appear blurry, with enhanced brightness over the equatorial region. With Webb, finer details are resolved within the bright, hazy band.”
The newly-discovered jet stream travels at about 515 km per hour, twice the sustained winds of a Category 5 hurricane here on Earth.
It is located around 40 km above the clouds, in…
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