New findings about Jupiter

 Jupiter and it's understanding of planet formation, New models offer clues

Jupiter’s atmosphere and clouds have mesmerized stargazers for centuries, as their multi-colored, swirling layers can easily be viewed from powerful telescopes on Earth. However, NASA’s Juno spacecraft has upped the ante regarding our understanding of Jupiter’s atmospheric features, having revealed them in breathtaking detail. This includes images of massive lightning storms, clouds swallowing clouds, polar vortices and powerful jet streams. Despite its beauty and wonder, scientists are still puzzled about the processes occurring deep inside Jupiter’s atmosphere which result in these incredible features. Jupiter now appears far wetter than long assumed, carrying more oxygen than the Sun itself. The finding reshapes how scientists think the largest planet came together and sharpens the rules used to explain how planets form anywhere. New simulations finally connect Jupiter’s cloud cover to the gases which seep upward from much deeper layers. 

At the University of Chicago (UChicago), Jeehyun Yang built a digital Jupiter which tracks both chemistry and motion. Her team also partnered with NASA’s Jet Propulsion Laboratory (JPL) scientists to capture how clouds and heat move together. By matching those deep processes to gases measured higher up, the model tightened the range for Jupiter’s oxygen. Now, a collaborative team of scientists from NASA and academia have provided new insights into the interior mechanisms of Jupiter’s atmosphere, with their findings being published. Through a series of computer models designed to simulate Jupiter’s interior mechanisms. Researchers used CO as a proxy tracer, an easier signal which stands in for another. Deep inside Jupiter, heat drives carbon and oxygen through reactions, and the balance controls how much CO survives. When vertical mixing lifts gas upward faster than chemistry can reset it, CO becomes a record of the deeper mix. The record only works if models get mixing speeds right, since faster churn can mimic different oxygen amounts.

After using a combination of a 1D chemistry-based model and a 2D hydrodynamic model, the team discovered that Jupiter contains about one and a half times more oxygen than the Sun. Additionally, the team found that the circulation patterns within Jupiter’s atmosphere are much slower than previously hypothesized. Discovering Jupiter’s higher-than-expected oxygen content could help scientists constrain planetary formation and evolution models, for both planets in our solar system, and beyond. “This is a long-standing debate in planetary studies,” said Dr. Jeehyun Yang, who is a postdoctoral researcher at the University of Chicago and lead author. “It’s a testament to how the latest generation of computational models can transform our understanding of other planets.” Work on disk snowlines, boundaries where key gases freeze into ice, outlined why carbon and oxygen separate. Beyond the water snowline, icy grains lock oxygen into solids, and planets can swallow the oxygen faster than vapor. If Jupiter gathered much of its mass where ices piled up, migration could later park it nearer the Sun. Similar element ratios now guide studies of exoplanets, since telescopes can compare water, methane, and CO together.

The Great Red Spot still spans about twice Earth’s width, but it only hints at deeper water. Water carries much of Jupiter’s oxygen, and it condenses into heavy clouds which trap it below the visible bands. NASA’s Galileo probe lasted about 58 minutes in 1995, and it avoided the wettest storms. One detailed report traced that dispute to the planet’s deep, unreachable hidden water. The amount of oxygen found in Jupiter’s atmosphere is almost negligible compared to the hydrogen and helium which largely comprises the largest planet in the solar system. However, these findings nonetheless profoundly change our understanding of Jupiter and its atmospheric composition and behavior. Along with helping scientists better understand how our own solar system formed and evolved, Jupiter is often used as an analog for gas giant exoplanets. Older studies treated chemistry and circulation separately, even though hydrodynamics, the physics of moving fluids, sets the pace. Rising gas cools and forms droplets, which changes which molecules react, and sinking gas reheats and reverses those changes. The team built the new model so cloud behavior and chemistry could constrain each other in the same run. Even with that coupling, the model still depends on laboratory reaction rates which remain uncertain under Jupiter-like pressures.

Since arriving at the Jovian system in 2016, Juno has profoundly changed our understanding of the largest planet in the solar system, along with providing breathtaking images. This includes discovering Jupiter’s poles exhibit several vortices, as opposed to a single large vortex on Saturn, along with discovering that Jupiter potentially lacks a solid rocky core, and instead has a “fuzzy” core comprised of heavy elements mixed with hydrogen. Microwave data pinned down water abundance in Jupiter’s equatorial air, and NASA’s Juno offered a rare check on deeper oxygen. Those waves pass through upper clouds, so the instrument sensed water vapor below, where sunlight cannot drive the chemistry. The new simulations landed near the lower end of that microwave range, easing tension between models and measurements. Jupiter’s water probably varies with latitude, so a single equatorial value cannot describe every storm system.

Additionally, Juno has obtained incredible images and gathered groundbreaking data regarding Jupiter’s four Galilean moons: Io, Europa, Ganymede, and Callisto. This includes imaging extreme volcanic activity on Io, finding that Europa’s ice shell thickness is different across the surface, confirmed that Ganymede has its own magnetic field, and finding that Callisto has internal activity despite it being comprised largely of ice. The research group described vertical mixing with eddy diffusion, a shortcut for how turbulence moves gas upward and downward. Their results implied diffusion ran 35 to 40 times slower than standard assumptions used in many Jupiter models. At that pace, a molecule could take several weeks to cross one layer, rather than doing it in hours. “It really shows how much we still have to learn about planets, even in our own solar system,” said Yang. The study also tracked the carbon-to-oxygen ratio, the balance of carbon compared with oxygen in Jupiter’s atmosphere. Galileo’s measurements showed Jupiter held extra carbon, and the new oxygen estimate leaves that carbon looking even more dominant. Carbon-rich solids and ices can form where water freezes out, and later accretion can preserve that imbalance. If Jupiter grew in such a patchy disk, other planetary systems may also build giants from materials that vary by region.

Juno’s mission was extended through September 2025, with plans to continue spacecraft operations until it runs out of fuel or ceases function. This is when NASA plans to intentionally have Juno crash into Jupiter’s atmosphere to avoid contaminating the Galilean moons with Earth’s microbes. This similar “retirement” was used for NASA’s Galileo spacecraft in Jupiter and NASA’s Cassini spacecraft in Saturn in September 2003 and September 2017, respectively. Direct sampling remains the cleanest way to confirm Jupiter’s deep water, because clouds can fool remote sensing. A dedicated entry probe could measure water vapor as it falls, and that reading would pin down oxygen. Meanwhile, long observing runs from Earth can track CO across latitudes, testing whether mixing stays slow everywhere. Any single probe path could still miss unusual pockets, so scientists will need repeated descents to map the full picture. By tying cloud physics, chemistry and slow circulation into one framework, researchers narrowed Jupiter’s oxygen story to a workable range. Future water measurements and mixing tests will decide how widely that framework applies, from our solar system to distant giants. What new insights into Jupiter’s interior will scientists make in the coming years and decades? What can Jupiter's interior continue to teach scientists about planetary formation and evolution, and specifically exoplanets? How much more data will Juno gather before the end of its mission? Only time will tell.