Scientists recently discovered the minor planet Chariklo is surrounded by rings, and an even more recent findings shows a second similar object possesses the same features.
The objects are members of a class of minor planets called centaurs, which have qualities of both asteroids and comets, MIT reported. In the past researchers believed centaurs were dormant, but these new findings suggest otherwise.
In November 2011, researchers observed the centaur Chiron pass in front of a bright star, blocking its light. The object's shadow allowed the team to analyze its features, and they identified what they believe to be a ring system. The feature could also be attributed to jets of material shooting out from Chiron's surface.
"It's interesting, because Chiron is a centaur-part of that middle section of the solar system, between Jupiter and Pluto, where we originally weren't thinking things would be active, but it's turning out things are quite active," said Amanda Bosh, a lecturer in MIT's Department of Earth, Atmospheric and Planetary Sciences.
An object without surrounding material would exhibit a straightforward pattern, but the observations of Chiron revealed symmetrical features, suggesting gas or dust could be blocking some of the starlight. The researchers believe the rings could have been formed when another body broke up, generating debris that were pulled into the centaur's orbit. The debris could have also been leftover from the creation of Chiron itself.
"Another possibility involves the history of Chiron's distance from the sun," said researcherJessica Ruprecht. "Centaurs may have started further out in the solar system and, through gravitational interactions with giant planets, have had their orbits perturbed closer in to the sun. The frozen material that would have been stable out past Pluto is becoming less stable closer in, and can turn into gases that spray dust and material off the surface of a body."
The findings were published in a recent edition of the journal Icarus.
