VATICANCITY -- Speculation started immediately after the surprise announcment Monday by Pope Benedict XVI that Feb. 28 would be his last day, with a conclave of cardinals meeting in March to pick a new pontiff.
Contenders to be his successor include Cardinal Angelo Scola, archbishop of Milan, Christoph Schoenborn, the archbishop of Vienna, and Cardinal Marc Ouellet, the Canadian head of the Vatican's office for bishops.
Longshots include Cardinal Timothy Dolan of New York. Although Dolan is popular and backs the pope's conservative line, being from a world power will probably not count in his favor. That might also rule out Cardinal Raymond Burke, an archconservative and the Vatican's top judge, even if he is known and respected by most Vatican cardinals. Burke used to be archbishop of St. Louis.
Antonio Marto, the bishop of Fatima in central Portugal, said Benedict XVI's resignation presents an opportunity to pick a church leader from a country outside Europe.
In Africa or Latin America, there is a freshness, an enthusiasm about living the faith, Marto told reporters. Perhaps we need a pope who can look beyond Europe and bring to the entire church a certain vitality that is seen on other continents.
Cardinal Antonio Tagle, the archbishop of Manila, has impressed many Vatican watchers, but at 56 and having only been named a cardinal last year, he is considered too young.
Cardinal Peter Kodwo Appiah Turkson of Ghana is one of the highest-ranking African cardinals at the Vatican, currently heading the Vatican's office for justice and peace, but he's something of a wild card.
There are several possibilities in Latin America, though the most well-known, Cardinal Oscar Andres Rodriguez Maradiaga of Honduras, is considered far too liberal to be elected by such a conservative College of Cardinals.
Whoever it is, he will face a church in turmoil: The sex abuse scandal has driven away thousands of people, particularly in Europe, from the church. Rival churches, particularly evangelical Pentecostal groups in the developing world, pose new competition. And as the pope himself has long lamented, many people in an increasingly secular world simply feel they don't need to believe in God.
All cardinals under age 80 are allowed to vote in the conclave, the secret meeting held in the Sistine Chapel where cardinals cast ballots to elect a new pope. As per tradition, the ballots are burned after each voting round; black smoke that snakes out of the chimney means no pope has been chosen, while white smoke means a pope has been elected.
There are currently 118 cardinals under age 80 and thus eligible to vote, 67 of whom were appointed by Benedict. However, four of them will turn 80 before the end of March. Depending on the date of the conclave, they may or may not be allowed to vote.
Benedict in 2007 passed a decree requiring a two-thirds majority to elect a pope, changing the rules established by John Paul who had decided that the voting could shift to a simple majority after about 12 days of inconclusive voting. Benedict did so to prevent cardinals from merely holding out until the 12 days had passed to push through a candidate who only had only a slim majority.