A discovery by University of Houston researchers has revealed a massive energy imbalance on Saturn, shedding new light on planetary science and evolution and challenging existing climate models for the Solar System’s gas giants. Findings published in publication Nature Communication.

“This is the first observation of a global energy imbalance on a seasonal scale in a gas giant,” said Laimin Li, professor of physics in the UH College of Life Sciences and Mathematics. “This not only gives us a new perspective on planet formation and evolution, but also changes the way we think about planetary and atmospheric science.”

Using data from the Cassini probe mission, Xinyue Wang, a third-year doctoral student in NSM’s Department of Earth and Atmospheric Sciences, discovered a significant and previously unknown seasonal energy imbalance on Saturn.

“Each planet receives energy from the sun in the form of solar radiation and loses this energy by emitting thermal radiation,” Wang said. said. “But like other gas giants, Saturn has another source of energy in the form of deep internal heat, and this affects its thermal structure and climate.”

The instability is due to Saturn’s large orbital eccentricity, which varies by about 20% from aphelion (the orbit’s farthest point from the Sun) to perihelion (the orbit’s closest point to the Sun); This causes large seasonal variations in absorbed light. Solar energy. . Unlike Saturn, Earth does not experience significant seasonal energy imbalances due to its very small orbital eccentricity.

“Earth has a measurable energy budget, but it is mainly determined by absorbed solar energy and emitted thermal energy,” said Xun Jiang, professor of atmospheric sciences. “Earth’s internal temperature is negligible, and its seasons last only a few months, compared to Saturn’s seasons of several years.”

The data also suggest that Saturn’s unbalanced energy budget plays an important role in the development of giant storms, the dominant weather phenomenon in the planet’s atmospheric system. This data can also provide insight into weather conditions on Earth.

“To our knowledge, the role of energy balance in the development of moist convective storms on Earth has not been fully investigated, so we plan to investigate this as well to see if there is a connection,” Wang said.

The Cassini mission, an ambitious joint effort by NASA, the European Space Agency and the Italian Space Agency, was launched in 1997 and has been exploring Saturn, its rings and moons for nearly 20 years. Professor Li was selected as a participating scientist to observe three onboard instruments that monitor Saturn’s radiative energy balance.

Wang, along with graduate students Larry Guan (Physics) and Tishkhan D. Karandana G and Ronald Albright (Earth and Atmospheric Sciences), conducted the research under the advice of Professors Li and Jiang.

“Current models and theories about the atmosphere, climate and evolution of gas giants assume that the global energy budget is balanced,” Wang said. “However, we believe that our discovery of this seasonal energy imbalance requires a re-evaluation of these models and theories.”

Lee’s team is now focused on other gas giants, including Uranus, where the flagship probe is planned for a mission in the next decade.

“Our data suggest that these planets will also have significant energy imbalances, especially Uranus, which we predict will have the strongest imbalance due to its orbital eccentricity and very large inclination,” Wang said. “What we are currently investigating will reveal limitations in current observations and formulate testable hypotheses that will benefit future flagship missions.”

In addition to the UH researchers, the study’s authors include scientists from NASA, the University of Wisconsin, the University of Maryland, the University of Central Florida, and the University of California, Santa Cruz, as well as scientists from France and Spain.