Ring around the asteroid: Scientists make surprise discovery

This is an artist's interpretation of the asteroid Chariklo.ESO/L. Calçada/M. Kornmesser/Nick Risinger

A faraway asteroid named Chariklo is traveling through space with two unusual companions: a couple of dense, narrow rings. The discovery came as quite a surprise. Multiple sites around South America, including the European Southern Observatory's La Silla Observatory in Chile, observed the extraordinary feature.

"This is the smallest object by far found to have rings, and only the fifth body in the Solar System -- after the much larger planets Jupiter, Saturn, Uranus, and Neptune -- to have this feature," the European Southern Observatory noted in a release about the find. There is no definitive answer as to how the rings got there, but scientists speculate they may have been created from a debris field caused by an impact, along with ice.

Icy Chariklo orbits the sun between Saturn and Uranus. One of its rings is just over four miles wide, while the other ring is just under two miles wide, making them quite slim. The rings were found during a routine observation as the asteroid passed in front of a star.

Chariklo is named for a mythological nypmh who was married to a centaur. The rings have been given their own nicknames, Oiapoque and Chuí, after two rivers located in Brazil. The presence of the rings may indicate the asteroid also has a small moon, or that the rings could eventually form into a moon. It's likely Chariklo isn't done surprising us yet."We weren't looking for a ring and didn't think small bodies like Chariklo had them at all, so the discovery -- and the amazing amount of detail we saw in the system -- came as a complete surprise!" says Felipe Braga-Ribas, the lead author of a paper on the find published in the journal Nature.

This artist's rendering shows what the view from inside the asteroid's rings might look like.