Black smoke vs. white smoke: What does each color mean during conclave?
The black and white smoke comes from a cast-iron stove inside the Sistine Chapel.
As the papal conclave continues, onlookers from around the world will watch for smoke in Vatican City, eager for the first update on who will be the next leader of the Catholic Church.
On the morning of May 7, 133 cardinals − the Catholic Church's most senior officials − gathered to vote on who they believe should be the next pontiff, succeeding Pope Francis. While this process is held in secrecy, the rest of the world is informed on the group's daily decisions by white or black-colored smoke funneled from the top of the Sistine Chapel. Black smoke indicates a non-conclusive answer, and white smoke indicates that a new pope has been selected.
Here's what to know about the black and white smoke used during a papal conclave.
What is a papal conclave?
A papal conclave is an election of a new pope, conducted by the College of Cardinals − bishops and Vatican officials selected by the pope. The cardinals are tasked with voting for one of their colleagues to take over the role of pontiff.
During the conclave, the cardinals are sequestered, and cannot communicate with the "outside world."
Before voting, the cardinals discuss the needs and challenges facing the Catholic Church. They then gather in St. Peter's Basilica to invoke the guidance of the Holy Spirit on who should be the successor, according to the United States Conference of Catholic Bishops.
For the actual election, the cardinals enter the Sistine Chapel, take an oath of secrecy and seal the church's doors. Each cardinal votes by secret ballot. He says a prayer and then drops his ballot in a large chalice, according to the United States Conference of Catholic Bishops.
If one candidate does not receive a two-thirds majority vote, another election is held. This process is repeated until one candidate has received the necessary votes.
The longest conclave in history lasted nearly three years (34 months) with the election of Pope Gregory X in 1271, according to EWTN Vatican. On the flip side, Pope Francis was elected just one day after the conclave began in 2013.
What does the black and white smoke mean during a conclave?
Black and white smoke is used to represent the cardinals' decisions each day, as they are sequestered and cannot share this news directly.
If one candidate doesn't receive the necessary two-thirds vote, the ballots are burned in a stove with a mixture of chemicals to produce black smoke. The black smoke indicates more voting is ahead.
If a candidate is selected, the final round of ballots are burned with chemicals to produce white smoke.
What time are the smoke signals?
There isn't an exact timing for the smoke signals that occur during a conclave, but experts use past conclaves to make educated guesses.
On May 7, the cardinals only conducted one round of voting, as the majority of the day was spent taking care of introductory business, including a special sermon led by one of the church's top officials, Matthew Gabriele, a medieval studies professor at Virginia Tech, previously told Paste BN.
Black smoke emerged from the Sistine Chapel chimney around 3 p.m. ET on May 7 and 5:50 a.m. ET on Thursday, May 8.
The cardinals can fit up to four rounds of voting in one day, if one candidate is not selected. If this is the case, Gabriele said smoke signals will occur around mid-morning, noon, mid-afternoon and evening.
In 2013, during the conclave in which Pope Francis was elected, the first black smoke signal was spotted at about 7:41 p.m. local time, America Magazine reported.
Where does the smoke come from?
The black and white smoke comes from a cast iron stove inside the Sistine Chapel. One of the stoves is used to burn the cardinals' ballots and the other is to send puffs of black or white smoke up above.
What chemicals are mixed with the ballots to produce black and white smoke?
During the 2013 conclave that elected Pope Francis, the black smoke was produced using a mixture of potassium perchlorate, anthracene (a component of coal tar) and sulfur.
The conclave used a combination of potassium chlorate, lactose and chloroform resin to create the white smoke.
What happens once a candidate is chosen?
Once a candidate has received two-thirds of the cardinals' votes, accepts the position and chooses his papal name, the senior cardinal deacon announces him from the balcony of St. Peter's balcony before the new pope steps out to face the crowd.
Editor's note: This story has been updated to add new links and new information.
Greta Cross is a national trending reporter at Paste BN. Story idea? Email her at gcross@usatoday.com.