  Until 2013, only the giant planets were known to host ring systems. In June
2013, a stellar occulation revealed the presence of narrow and dense rings
around Chariklo, a small Centaur object that orbits between Saturn and Uranus.
Meanwhile, the Cassini spacecraft revealed evidence for the possible past
presence of rings around the Saturnian satellites Rhea and Iapetus. Mars and
Pluto are expected to have tenuous dusty rings, though they have so far evaded
detection. More remotely, transit events observed around a star in 2007 may
have revealed for the first time exoplanetary rings around a giant planet
orbiting that star. So, evidence is building to show that rings are more common
features in the universe than previously thought. Several interesting issues
arising from the discovery (or suspicion) of new ring systems are described in
this chapter.
