Rings around a tiny body have changed over the past decade

The dwarf planet Quaoar, located far beyond Neptune, is notable for its enigmatic ring system, which has undergone changes over the past decade. Discovered in 2021, Quaoar's first ring orbits at an unusual distance of 4,057 kilometers from its center, approximately three times its Roche limit, which is estimated at 1,780 kilometers. A second ring was identified in 2022, orbiting closer at 2,520 kilometers, yet still outside the Roche limit. The existence of these rings so far from the dwarf planet's body challenges conventional models of planetary ring formation, as rings outside this limit are generally expected to coalesce into moons within a century. This has led astronomers to revise their understanding of how planetary rings can survive. Quaoar itself measures about 1,110 kilometers in diameter, roughly half the size of Pluto, and has a small moon named Weywot, which is 80 kilometers in diameter.