Uranus’s Distant Rings Reveal Two Separate Origins

Astronomers using Keck, Webb, and Hubble analyzed Uranus’ faint outer rings and found two distinct compositions: the blue μ ring consists of tiny icy grains likely sourced from Mab, while the red ν ring is rocky with about 10–15% carbon-rich organics, suggesting different formation histories for the planet’s second ring system. The study, published in the Journal of Geophysical Research: Planets, highlights how ring material traces back to source bodies and collisions, with implications for Uranus’s formation and a need for future close-up observations.