James Webb reveals surprising changes in Chariklo’s two mysterious rings

Credit: L. Maquet, Observatoire de Paris In 2013, astronomers discovered two narrow rings around Chariklo, a 250-kilometre-wide minor planet orbiting between Saturn and Uranus, marking the first time rings had been found around such a small body. Nine years later, the James Webb Space Telescope observed the same system during a rare stellar occultation and found that the inner ring had become noticeably more opaque while the outer ring appeared weaker and more transparent. This opposite evolution suggests that Chariklo's rings are far more dynamic than previously thought, changing on timescales of just a few years rather than remaining stable over centuries, according to a study led by the Institute of Astrophysics of Andalusia and reported by EurekAlert.A tiny world with giant-planet featuresChariklo, formally known as 10199 Chariklo, is classified as a centaur, a type of icy minor planet that orbits in the outer Solar System between the giant planets. With a diameter of only about 250 kilometres, it is tiny compared to Saturn or Uranus, yet it hosts a ring system that rivals those worlds in complexity. The two rings, designated C1R and C2R, are extremely narrow and lie close to t...