The eyes of the world's Catholics are turned toward the Vatican, where 115 cardinals begin choosing a new pope Tuesday.
The College of Cardinals will seclude themselves in the Sistine Chapel and not come out until a new pope is elected. There is no telling how long it will take. But the world will know when the church has a new leader when white smoke billows from a special chimney installed on the chapel roof.
Their selection must receive at least 77 votes - a two-thirds majority. There is no clear favorite.
Newly elected Pope Francis, Cardinal Jorge Mario Bergoglio of Argentina, appears on the balcony of St. Peter's Basilica at the Vatican, March 13, 2013.
April 4, 2005: Jorge Mario Bergoglio conducts a mass in honor of Pope John Paul II at the Buenos Aires cathedral. Bergoglio of Argentina was elected pope on March 13, 2013 to lead the Roman Catholic Church.
Crowds cheer as white smoke rises from the chimney above the Sistine Chapel in the Vatican, March 13, 2013.
White smoke rising from the chimney on the Sistine Chapel, indicating that a new pope has been elected.
Crowds cheer as white smoke rises from the chimney above the Sistine Chapel, March 13, 2013.
Nuns smile in Saint Peter's Square at the Vatican, March 13, 2013.
People crowd Saint Peter's Square to await the sight of smoke from the chimney above the Sistine Chapel.
Visitors wait in Saint Peter's Square during the second day of voting, March 13, 2013.
Black smoke rises from the chimney on the roof of the Sistine Chapel in the Vatican City indicating that no decision has been made after the first day of voting for the election of a new pope, March 12, 2013.
The crowd waits during the conclave in Saint Peter's Square at the Vatican, March 12, 2013.
A view of the balcony on the facade of Saint Peter's Basilica where the newly elected pope will make his first appearance to salute the cheering crowd, at the Vatican, March 11, 2013.
Saint Peter's Basilica at the Vatican is silhouetted during sunset in Rome, March 11, 2013.
Saint Peter's Square, seen from the dome of Saint Peter's Basilica at the Vatican.
Some Vatican observers say the Church is badly in need of reform after the child sex scandal and what they see as a growing irrelevancy of Church doctrine. They predict the cardinals will elect a younger pope. But the experts also say the more traditional-minded cardinals will push for a conservative.
Pope Benedict surprised the world last month, when after eight years he became the first Roman Catholic Church leader in 600 years to step down voluntarily.
The cardinals will officially enter the conclave at 5:00 p.m. local time Tuesday. The first possible smoke sighting from the Sistine Chapel chimney should emerge around 7:00 p.m. There will be no more than four votes per day until a new pope is chosen.