A papal resignation is a rare event. The last time a pope resigned, Christopher Columbus hadn't been born yet.
A Vatican spokesperson said this morning that a papal election is expected by mid-March.
So how exactly does the Vatican elect its leader?
It all begins with a meeting known as a papal conclave, where the College of Cardinals elects a pope by ballot. The college is a goup of cardinals—usually more than a hundred—that convenes at the Vatican to choose a successor after a pope's death or resignation.
A conclave starts no sooner than 15 days and no later than 20 days after a pope's death. But in rare cases of resignation, with no mourning period, the conclave usually starts earlier.
To vote, the cardinals enter the Sistine Chapel of the Apostolic Palace. They are prohibited from contact with the outside world, and all participants must take an oath, swearing absolute secrecy.
If a candidate fails to receive a two-thirds majority vote, then four ballots—two in the morning, and two in the afternoon—are held each successive day until a two-thirds majority is reached. The conclave may elect any baptized male, though selecting a layman is highly unlikely.
When the College of Cardinals fails to reach a two-thirds majority vote, the Vatican releases black smoke from a chimney on the Sistine Chapel, signaling an unsuccessful election. If a candidate wins enough votes, white smoke rises from the chimney, and the world's one billion Catholics have their new leader.