Sonda Juno a realizat două descoperiri fascinante despre Jupiter.

NASA’s Juno mission has unveiled remarkable discoveries about Jupiter, particularly its chaotic atmosphere and its volcanic moon, Io. Juno entered Jupiter’s system in 2016, but technical issues led to its wide polar orbit, allowing it to pass close to the planet and its moons approximately every 53 days. Despite this limitation, Juno has gathered an impressive amount of high-quality data about Jupiter’s atmosphere, especially the polar regions.

### Atmospheric Discoveries

One major finding is the existence of a stratospheric haze “dome” at Jupiter’s north pole, which is 11 degrees Celsius cooler than the surrounding area. Violent jet streams with speeds exceeding 160 km/h swirl around this polar cap. Below the haze lies a massive central cyclone, approximately 3,000 km in diameter, surrounded by eight smaller cyclones, each ranging from 2,400 to 2,800 km. These sizes far exceed any cyclone phenomena seen on Earth.

Since 2016, Juno has observed the movement of these cyclones using visible light and infrared measurements, tracking their behavior and interactions. The cyclones are slowly drifting toward the pole via a process called “beta drift,” similar to what happens with terrestrial cyclones due to interacting forces: the Coriolis effect alongside the circular wind patterns typical of cyclones. Unlike Earth, where cyclones lose energy as they approach polar regions and cannot sustain themselves, Jupiter’s unique atmospheric dynamics allow these cyclones to maintain energy and eventually collide at the poles. This interaction not only stabilizes their configuration but also creates oscillations as they drift westward like clock hands.

### Discoveries About Io

In addition to atmospheric studies, Juno has conducted multiple flybys of Io, recognized as the most volcanically active body in the solar system. On December 27, 2024, Juno recorded the strongest volcanic eruption ever observed on Io, showcasing the moon’s intense geologic activity. During a subsequent flyby, data indicated that the volcanic activity was still ongoing, with further observations anticipated as Juno prepares for additional encounters.

Significantly, Juno’s findings beneath Io’s surface could reshape current understandings of its geology and volcanic processes. By integrating data from its Microwave Radiometer (MWR) with infrared images from the Jovian Infrared Auroral Mapper (JIRAM), researchers discovered signs of hot, flowing magma beneath Io’s cooling crust. This surprising revelation indicates active magma flows, suggesting that about 10% of Io’s subsurface is filled with molten rock, providing an efficient mechanism for heat transfer from the moon’s interior to the surface.

These findings challenged prior theories suggesting the existence of a subterranean ocean of magma. Instead, the detected upwelling of magma offers insights into how internal heat reaches the surface, resulting in the frequent volcanic eruptions.

Shannon Brown from NASA’s Jet Propulsion Laboratory described this process, likening Io’s volcanic systems to a car radiator, effectively transferring internal heat to the exterior and cooling the surface in the cold expanse of space.

The latest research results were shared during the General Assembly of the European Geosciences Union in Vienna in late April, emphasizing the mission’s significant contributions to our understanding of Jupiter and its moons.

### Conclusion

NASA’s Juno mission has fundamentally enhanced our knowledge of Jupiter’s atmosphere and its moon Io, revealing complex interactions and geological processes at play. The data gathered not only informs about the dynamics of the gas giant and its volcanic companion but also raises new questions about the evolution and behavior of celestial bodies in our solar system. As Juno continues its mission, further discoveries are expected, possibly uncovering more secrets of these fascinating worlds.