Researchers have resolved a long-standing puzzle about Saturn's apparent changing rotation rate. Observations from the James Webb Space Telescope show that the planet's aurora drives a self-sustaining cycle of atmospheric heating and winds. The findings were published in the Journal of Geophysical Research: Space Physics.
For years, measurements from NASA's Cassini spacecraft in 2004 had suggested Saturn's rotation rate was shifting over time. Planets cannot alter their spin rates so quickly, leaving scientists puzzled. A 2021 study had pointed to atmospheric winds affecting auroral signals but could not identify the cause of those winds.