NASA’s Juno mission has unveiled new insights into Jupiter’s fierce winds, cyclones, and volcanic activity on its moon, Io. The findings at the European Geosciences Union General Assembly on April 29 provide a deeper understanding of the gas giant’s atmospheric dynamics and Io’s fiery surface.
Juno’s latest data has helped scientists refine a new model explaining the fast-moving jet stream that encircles Jupiter’s north pole, where massive cyclones swirl in a chaotic dance.
Unlike Earth’s hurricanes, which dissipate before reaching the poles, Jupiter’s cyclones cluster together, interacting like springs in a mechanical system. This beta drift effect causes them to oscillate and drift westward, stabilizing their positions.
Radio occultation experiments have revealed that Jupiter’s north polar stratospheric cap is 11°C cooler than surrounding regions, with winds exceeding 100 mph (161 kph).
Juno’s microwave radiometer (MWR) and Jovian Infrared Auroral Mapper (JIRAM) have provided Io’s first-ever subsurface temperature profile, revealing still-warm magma beneath its cooled crust. Scientists have found that approximately 10% of Io’s surface consists of slowly cooling lava, which explains how the moon rapidly renews its surface.
One of the most energetic eruptions in Io’s recorded history, first detected during Juno’s December 27, 2024, flyby, was still spewing lava and ash as recently as March 2. Scientists expect more observations on May 6, when Juno flies 55,300 miles (89,000 km) past the moon.
Juno’s ever-changing orbit allows it to explore new regions of Jupiter’s complex system, including the planet’s intense radiation belts. As Scott Bolton, Juno’s principal investigator, says, “Juno is built like a tank, and we’re learning more about this extreme environment each time we go through it.”
