Scientists have pierced through Jupiter’s thick cloud cover using advanced computer simulations, revealing that the gas giant contains approximately one and a half times more oxygen than the sun. This discovery helps settle a decades-long debate and provides crucial insights into how our solar system’s largest planet formed billions of years ago.
The breakthrough comes from researchers at the University of Chicago and NASA’s Jet Propulsion Laboratory, who published their findings in The Planetary Science Journal on January 8. Their work represents the most comprehensive model of Jupiter’s atmosphere ever created, combining two previously separate approaches to understanding planetary atmospheres.
Peering Beneath the Storms
Jupiter’s atmosphere has fascinated astronomers for over 360 years, ever since early telescope observations revealed the Great Red Spot. This massive storm, roughly twice Earth’s size, has been churning for centuries and is just one feature in a planet-wide system of violent winds and dense clouds.
Despite this long history of observation, what lies beneath Jupiter’s visible surface remains largely mysterious. The clouds are so thick that NASA’s Galileo spacecraft lost contact with Earth in 2003 as it descended into the deeper atmosphere. Currently, NASA’s Juno mission studies the planet from orbit, measuring components in the upper atmosphere including ammonia, methane, ammonium hydrosulfide, water, and carbon monoxide.
The challenge is that much of Jupiter’s oxygen is locked in water, which condenses into heavy clouds far below the visible bands, beyond the reach of orbiting instruments.
A New Modeling Breakthrough
Jeehyun Yang, a postdoctoral researcher at the University of Chicago and lead author of the study, recognized that previous research had treated atmospheric chemistry and fluid dynamics as separate problems. This approach led to wildly conflicting estimates of Jupiter’s water and oxygen content, with one major recent study suggesting the planet held only about a third as much oxygen as the sun.
Yang and her team took a different approach by combining chemistry and hydrodynamics into a single model for the first time at this level of detail. The simulation tracks how molecules travel between the extremely hot conditions deep within Jupiter’s atmosphere and the cooler upper regions, undergoing thousands of different chemical reactions while also accounting for cloud and droplet behavior.
The researchers used carbon monoxide as a tracer to infer deeper oxygen levels, since this gas provides clues about the chemical conditions in Jupiter’s interior as it circulates upward.
Implications for Planetary Formation
The finding that Jupiter contains about one and a half times the sun’s oxygen content has significant implications for understanding planetary formation. All elements that make up planets originated in the sun, but variations in their proportions offer clues about where and how planets formed.
The enhanced oxygen level supports theories that Jupiter formed beyond the snow line, where water froze into ice in the early solar system. Ice is much easier for growing planets to accumulate than water vapor, meaning a planet forming in this cold region would naturally incorporate more oxygen-rich frozen material than the sun itself.
This knowledge extends beyond our solar system, helping scientists predict what kinds of planets might form around other stars and which ones could potentially support life.
Slower Circulation Than Expected
The model also revealed an unexpected finding about how Jupiter’s atmosphere moves. Gases appear to circulate vertically through the atmosphere 35 to 40 times more slowly than standard assumptions predicted. A single molecule might take several weeks to travel through one atmospheric layer, rather than just hours.
This slower mixing affects how heat, storms, and chemical reactions interact deep within the planet, potentially reshaping scientists’ understanding of Jupiter’s internal dynamics.
The study used microwave data from Juno to verify water abundance in Jupiter’s equatorial atmosphere, helping validate the model’s predictions. However, the researchers acknowledge that Jupiter’s water content likely varies with latitude, and a single equatorial measurement cannot describe every storm system across the planet’s surface.
Future missions may include dedicated entry probes that can directly sample water vapor as they descend, which would provide definitive measurements of Jupiter’s oxygen content. Meanwhile, continued observations from Earth can track carbon monoxide across different latitudes to test whether the slow mixing pattern holds throughout the atmosphere.
