Worlds (Worlds, #1)

"In the year 2084, nearly a half million humans have escaped pollution and overcrowding to live in the hollowed-out asteroids miles above the Earth. For Maryanne O'Hara--born and raised on New New York, one of several orbiting Worlds--the prospect of attending college on the home planet is both frightening and exhilirating. But things are very different down below. Violence, unrest and political fanatacism run rampant. And mixing with the wrong crowd can have serious, sinister and Worlds-shattering consequences."