Thick, swirling clouds cover Jupiter from pole to pole. They hold water like Earth\u2019s clouds, but at far greater density. For decades, those clouds have blocked a clear view of what lies beneath. Now, researchers from the University of Chicago and NASA\u2019s Jet Propulsion Laboratory say they have built the most complete picture yet of Jupiter\u2019s deep atmosphere.<\/p>\n
The new study, published in The Planetary Science Journal<\/a>, combines advanced chemistry with realistic atmospheric motion. The work helps settle a long-running debate about how much oxygen Jupiter contains and offers new clues about how the solar system formed.<\/p>\n \u201cThis is a long-standing debate in planetary studies,\u201d said Jeehyun Yang, a postdoctoral researcher at the University of Chicago<\/a> and the study\u2019s first author. \u201cIt\u2019s a testament to how the latest generation of computational models can transform our understanding of other planets.\u201d<\/p>\n Early telescope users recorded what is now known as the Great Red Spot, a vast storm twice Earth\u2019s size that still rages today. (CREDIT: NASA\/JPL-Caltech\/SwRI\/MSSS\/Kevin M. Gill) A Planet Shaped by Storms<\/p>\n Astronomers have watched Jupiter\u2019s storms for more than 360 years. Early telescope users recorded what is now known as the Great Red Spot, a vast storm twice Earth\u2019s size that still rages today. Fierce winds and deep cloud layers cover the entire planet in shifting patterns.<\/p>\n What happens below those clouds remains difficult to measure. In 2003, NASA\u2019s Galileo probe<\/a> plunged into Jupiter\u2019s atmosphere and lost contact as conditions became too extreme. NASA\u2019s Juno spacecraft now studies the planet from orbit, measuring gases in the upper atmosphere such as ammonia, methane, water vapor, and carbon monoxide.<\/p>\n Those measurements offer hints but not a full answer. Oxygen, a key element, is mostly locked in water. Under Jupiter\u2019s conditions, water condenses into clouds, making it uneven and hard to track directly.<\/p>\n Why Oxygen Matters<\/p>\n Every planet formed from the same basic material as the Sun. Differences in element amounts act like fingerprints of how and where planets grew. For Jupiter<\/a>, oxygen plays a central role. Much of it is tied up in water, which freezes far from the Sun but stays vapor closer in. Ice gathers more easily than vapor, so oxygen levels can hint at where Jupiter formed before settling into its current orbit.<\/p>\n<\/p>\n Past studies disagreed sharply. Some suggested Jupiter holds far less oxygen than the Sun. Others, including recent findings from Juno, pointed to higher values.<\/p>\n Yang and her colleagues saw a way forward by modeling carbon monoxide instead. Carbon monoxide is stable deep in Jupiter\u2019s atmosphere and easier to detect. By tracking how it forms and moves, scientists can infer how much oxygen must exist below the clouds.<\/p>\n New Tools for an Old Question<\/p>\n Earlier models often simplified Jupiter\u2019s atmosphere<\/a> into a single vertical column. They relied on hand-built chemical networks and assumed mixing rates. Those choices left large uncertainties.<\/p>\n The new study takes a different approach. The team built an automated chemical network that includes nearly 2,000 reactions among 89 chemical species. They paired this with a two-dimensional hydrodynamic model that simulates how gases move, rise, and sink near Jupiter\u2019s water cloud layer.<\/p>\n \u201cYou need both,\u201d Yang said. \u201cChemistry is important but doesn\u2019t include water droplets or cloud behavior. Hydrodynamics alone simplifies chemistry too much. So, it\u2019s important to bring them together.\u201d<\/p>\n The time-dependent behavior of the horizontally averaged CO mole fraction for four different oxygen abundance scenarios using SNAP\u22122D hydrodynamic modeling. (CREDIT: The Planetary Science Journal) One Reaction, Big Consequences<\/p>\n “A key focus involved the so-called Hidaka reaction, which breaks methanol into smaller molecules. For years, scientists argued over whether to include it and how fast it proceeds. Some older models used incorrect rates, which skewed results,” Yang told The Brighter Side of News<\/a>.<\/p>\n “By revisiting laboratory data and modern calculations, our team clarified the reaction\u2019s role. In older models, changing this single reaction could alter results by tenfold. In the new network, its impact was far smaller. That stability comes from capturing many competing chemical pathways at once,” he continued.<\/p>\n What the Models Reveal<\/p>\n When the researchers ran traditional one-dimensional models using the improved chemistry, they found that standard mixing assumptions favored low oxygen levels. That clashed with Juno\u2019s observations unless mixing was far weaker than usually assumed.<\/p>\n The two-dimensional simulations told a different story. By allowing atmospheric motion to emerge naturally, these models consistently matched observations when Jupiter\u2019s oxygen level ranged from about one to one and a half times that of the Sun.<\/p>\n The temperature dependence of the rate coefficients for the reaction CH3OH + H\u2192CH3 + H2O from various references. (CREDIT: The Planetary Science Journal) <\/p>\n The simulations also suggested that Jupiter\u2019s atmosphere mixes more slowly than long believed. A single molecule might take weeks, not hours, to move through certain layers.<\/p>\n \u201cOur model suggests the diffusion would have to be 35 to 40 times slower compared to what the standard assumption has been,\u201d Yang said.<\/p>\n Clues to Jupiter\u2019s Birth<\/p>\n An oxygen level slightly above solar, paired with Jupiter\u2019s known carbon enrichment, implies a high carbon-to-oxygen ratio. That points to a birthplace rich in carbon-bearing material but relatively poor in water ice.<\/p>\n