Scientists utilize Webb to quantify rapid jet stream in Jupiter’s atmosphere

Scientists have made an exciting discovery at Jupiter’s equator using the James Webb Space Telescope. They have found a high-speed jet stream that had previously gone unnoticed. This newfound jet stream will provide valuable insights into how the layers of Jupiter’s turbulent atmosphere interact.
The discovery was made on July 27, 2022, when the James Webb Space Telescope observed Jupiter’s lower stratosphere. The images obtained allowed scientists to measure winds of up to 515 kilometers per hour, which is about twice the sustained winds of a category five hurricane on Earth. The jet stream is located 40 kilometers above the clouds and is approximately 4,800 kilometers wide, making it relatively narrow compared to the immense size of Jupiter.
Lead author Ricardo Hueso of the University of the Basque Country in Bilbao, Spain expressed his surprise at this discovery. He noted that what was once seen as blurred hazes in Jupiter’s atmosphere now appear as crisp features that can be tracked along with the planet’s fast rotation.
Before the James Webb Space Telescope’s observations, scientists had only been able to characterize the winds in Jupiter’s troposphere, the layer below the stratosphere. They used ground-based telescopes and NASA’s Hubble Space Telescope to measure winds at cloud level by tracking the movement of clouds in Jupiter’s atmosphere. However, these previous observations did not reveal much detail in the haze above Jupiter’s clouds.
The James Webb Space Telescope’s suite of infrared instruments has allowed scientists to obtain detailed images of the entire planet across a broad spectrum of light. This has enabled them to discern and track faint details in Jupiter’s equatorial hazes for the first time.
To observe Jupiter, the researchers had to limit the frequencies of light they observed. They used filters on the telescope’s Near-Infrared Camera (NIRCam) to dim the planet enough for observation and to target specific altitudes for their observations.
Co-author Leigh Fletcher of the University of Leicester in the United Kingdom emphasized the significance of this discovery. Despite years of tracking Jupiter’s clouds and winds from a high number of observatories, there is still much to learn about the planet. Features like this jet stream can remain hidden from view until new observations are made.
To fully understand the dynamics of Jupiter’s atmosphere and the newly discovered jet stream, scientists compared the images from the James Webb Space Telescope with observations from NASA’s Hubble Space Telescope. They observed how the jet stream interacted with the cloud layer below it and measured how fast the winds changed with altitude, causing wind shears.
Scientists have long speculated about the existence of this jet stream. Early hints were provided by ultraviolet (UV) images captured by NASA’s Cassini spacecraft in 2000 when it flew by Jupiter on its way to Saturn. However, measurements from Cassini did not lead to firm conclusions due to the low contrast in the UV images.
Further insights into equatorial jet streams were gained from Cassini’s mission to Saturn, where similar jet streams were discovered. By studying the differences and similarities between Jupiter and Saturn, researchers hope to unravel the mechanisms that shape weather patterns around the equators of fast-rotating giant planets.
The James Webb Space Telescope’s Early Release Science program has provided valuable data for this study. The program was designed to demonstrate the telescope’s full potential and explore its capabilities. It has already yielded new findings on Jupiter’s rings, satellites, and atmosphere.
The results of this study were published in Nature Astronomy on October 19, 2023. This discovery highlights the importance of continued exploration and observation of our solar system’s planets. The James Webb Space Telescope has already proven its ability to uncover new insights and push the boundaries of our understanding. With future observations, scientists will be able to further investigate the dynamics of Jupiter’s atmosphere and track changes in its jet stream over time.