Cardinals attends a mass in St. Peter's Basilica at the Vatican March 12, 2013. All cardinals, including those over 80 who will not vote in the conclave, celebrate Mass in St Peter's Basilica to pray for the election of the new pope. The Mass is called "Pro Eligendo Romano Pontefice" ("For the Election of the Roman Pontiff") and is open to the public. [Photo: Reuters]