Scientific classifications are not usually clean. Usually when we think we have objects classified into groups, along comes a new piece of data that blurs the line. Centaurs are one of these blurring data points. They are the same size and (mostly) the same composition as asteroids. But they exist in a different location, between Jupiter and Neptune, NOT between Jupiter and Mars. And most confusing, they have rings. New research now shows the origins of these rings – turns out these two aspects of strange location and presence of rings are connected! In an orbit so far out from the Sun, they get pulled and pushed by the large planets, breaking them up, and forming the rings.
Add confusing facet number 1 to confusing facet number 2, and both elements of confusion are explained.