Something Fishy in Jupiter: James Webb Telescope catches fast-moving jet stream near planet’s equator

NASA’s James Webb Space Telescope has unveiled a striking feature within Jupiter’s atmosphere, shedding new light on the intricacies of the planet’s weather dynamics. NASA scientists have identified a massive high-speed jet stream in Jupiter’s atmosphere, a discovery that promises to deepen our understanding of the gas giant. A team of astronomers recently unveiled this swift jet stream, racing at an astonishing speed of 515 kilometres per hour, situated approximately 40 kilometres above Jupiter’s equator, within the lower stratosphere. NASA made this announcement on October 19th. The newfound high-speed jet stream, spanning an impressive 4,800 kilometres in width, hovers above Jupiter’s equator, far above its primary cloud layers. The lead author of the study, Ricardo Hueso from the University of the Basque Country, Spain, expressed his surprise at this remarkable discovery. “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,” said Hueso. Previously, the hazy obscurity in Jupiter’s atmosphere has transformed into clearly defined and traceable features, all thanks to the capabilities and precision of NASA’s James Webb Telescope. This newfound clarity empowers scientists to observe and follow these characteristics as they move with Jupiter’s swift rotation. The recently uncovered jet stream has been determined to reach speeds of up to 500 kilometres per hour, equivalent to twice the sustained winds of a Category 5 hurricane on Earth. This revelation occurred at an altitude of approximately 40 kilometres above Jupiter’s cloud cover within the lower stratosphere, providing a captivating insight into the planet’s atmospheric dynamics. The research team conducted a comparison of the observed winds at the upper layers using Webb and the lower layers with the Hubble Space Telescope, enabling them to identify wind shears and variations in wind speed with altitude. Furthermore, further observations are anticipated to reveal whether the jet stream’s speed and altitude undergo changes over time. This remarkable discovery was made possible by analysing data collected using Webb’s Near-Infrared Camera (NIRCam) in July 2022. Imke de Pater from the University of California, Berkeley, and Thierry Fouchet from the Observatory of Paris orchestrated an Early Release Science program that captured images of Jupiter every 10 hours over the course of one Jupiter day. The unique phenomenon became visible through a combination of four different filters that were sensitive to changes at various altitudes within Jupiter’s atmosphere. This breakthrough adds to our growing body of knowledge about Jupiter’s ever-evolving weather patterns, as previous missions, such as NASA’s Juno and Cassini, along with the Hubble Space Telescope, have also observed the planet’s dynamic atmospheric conditions.