Near the base of Asteroid Belt (5.11) is the remains of a motorcycle that is said to have exited the top of the Dome with its unfortunate rider on board.
As the story goes, a party was being held on top of the Dome, one night in the early 70s. One motorcycle-riding party-goer proceeded to do donuts, in ever-widening circles, before suddenly straightening out and riding off into the night.