A major energy imbalance has been discovered on Saturn: ScienceAlert

Will Saturn’s shenanigans never end? Scientists have found that the ringed planet suffers from a massive seasonal energy imbalance across the globe.

This discovery represents a turning point in our understanding of weather and climate on gas giant planets, their long-term evolution, and ongoing changes.

“This is the first time that a global energy imbalance on a seasonal scale has been observed on a gas giant.” says physicist Liming Li From the University of Houston. “Not only does this give us new insight into planetary formation and evolution, it also changes the way we should think about planetary and atmospheric science.”

Here’s what that means. The powerful sunlight streaming throughout the solar system imbues everything it hits with energy. Planets also lose energy as cooling, and radiate out into space primarily as thermal radiation.

In the case of gas giant planets, including Saturn, there is also an energy source flowing away deep within them that affects the planet’s climate from within.

A team led by atmospheric scientist Xinyu Wang of the University of Houston was studying Cassini data on Saturn to examine its brightness when they noticed something interesting. The difference between how much energy it absorbs compared to how much energy it emits can vary by up to 16 percent, with fluctuations in keeping with the planet’s seasons.

After careful examination, the researchers found that this relates to how far Saturn is from the Sun at any given time. Saturn’s orbit is not perfectly circular; It’s actually elliptical in shape — a property called eccentricity — resulting in a roughly 20 percent distance difference between its closest distance to the Sun and its farthest.

When Saturn is closer, it receives much more radiation from the Sun than when it is farther away, leading to a seasonal energy imbalance. This is very different from the way the Earth works; Its orbit is more circular, so we don’t experience the same sharp contrast.

This isn’t what anyone expected for the gas giants either.

“In current models and theories of the atmosphere, climate, and the evolution of gas giants, the global energy budget is assumed to be balanced.” Wang explains. “But we believe that our discovery of this seasonal energy imbalance requires a re-evaluation of those models and theories.”

This would mean that Saturn’s unbalanced energy could play an as-yet-unknown role in generating massive convective storms that burrow deep into the atmosphere, and that similar processes might occur at other gas giant planets, such as Jupiter, whose eccentricity is only less pronounced. A little bit of Saturn.

It could also help us understand the weather on Earth a little better, where the energy imbalance is much less significant, but still not zero. Other gas-covered planets, such as Neptune and Uranus, whose insufficiently examined inner and outer workings remain a great mystery to us humans.

“Our data suggest that these planets will have significant energy imbalances as well, especially Uranus, which we expect will have the strongest imbalance due to its orbital eccentricity and very high inclination.” [tilt]”, Wang He says.

“What we investigate now will identify limitations in current observations and formulate testable hypotheses that will benefit that future major mission.”

Never change, Saturn.

The research was published in Nature Communications.