Researchers using the NASA/ESA/CSA James Webb Space Telescope’s NIRCam (Near-Infrared Camera) have discovered a high-speed jet stream sitting over Jupiter’s equator, above the main cloud decks.
Researchers spotted several wind shears, or areas where wind speeds change with height or distance, which enabled them to track the jet. 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.
This image highlights several of the features around Jupiter’s equatorial zone that, during one rotation of the planet (10 hours), are very clearly disturbed by the motion of the jet stream. The discovery of this jet provides insight into how the layers of Jupiter’s famously turbulent atmosphere interact with each other, and how Webb is uniquely capable of tracking those features. Researchers are looking forward to additional observations of Jupiter with Webb to determine if the jet’s speed and altitude change over time.
These results were recently published in a paper in Nature Astronomy.
These findings may help inform ESA’s Jupiter Icy Moons Explorer, Juice, which was launched on 14 April 2023. Juice will make detailed observations of the giant gas planet and its three large ocean-bearing moons — Ganymede, Callisto and Europa — with a suite of remote sensing, geophysical and in situ instruments.
Juice will focus on unveiling Jupiter’s atmosphere upwards from the cloud tops. It will probe how temperatures, wind patterns and chemistry are changing in Jupiter’s atmosphere to answer questions such as: What is the weather and climate like on Jupiter? How does an atmosphere work when there is no solid surface?