Catholic Cardinals meet for Mass in the Vatican

US cardinal Sean Patrick O'Malley participates in a Mass for the election of a new pope, at the St Peter's basilica on March 12, 2013 at the Vatican. The 115 cardinal electors who pick the next leader of 1.2 billion Catholics in a conclave in the Sistine Chapel will live inside the Vatican walls completely cut off from the outside world until they have made their choice. UPI/Stefano Spaziani