According to New Scientist...
If we ever make black holes on Earth, they might be much stranger objects than the star-swallowing monsters known to exist in space. According to a new theory, any black hole that pops out of the Large Hadron Collider under construction in Switzerland might be surrounded by a black ring – forming a microscopic "black Saturn".
A black hole and a black ring can co-exist, in theory, as long as they are set spinning, say Henriette Elvang of MIT in Cambridge, US, and Pau Figueras of the University of Barcelona in Spain. "If you just had a ring, it would collapse. It's essential that it rotates to keep balanced," Elvang told New Scientist.