Cardinal Robert Prevost, whose papal name will be Pope Leo XIV, has become the first North American pope.

The appointment will probably please Donald Trump, as Vatican insiders previously remarked that the US had more than enough geopolitical influence without taking over the papacy.

A Vatican insider said: “He was not one of the obvious candidates, but he knows everybody, he spent 30 years as a missionary, he has languages.

“His time in Peru means he is one of the least ‘American’ of the American cardinals. But he understands America and he can speak to the country, which is important in the Trump era.”

Cardinal Prevost, 69, who was born in Chicago, has an impressive CV.

He spent years in Peru, first as a missionary and then as an archbishop.

He is seen as a reformer in the mould of Pope Francis, who sent Cardinal Prevost to run the diocese of Chiclayo, Peru, in 2014.

Cardinal Prevost liked the country so much that he acquired Peruvian citizenship in 2015.

He ran the diocese until 2023, when Francis brought him to Rome to be head of the Vatican’s Dicastery for Bishops, which in charge of vetting nominations for senior clergy around the world.

Cardinal Prevost was also the president of the Pontifical Commission for Latin America, a job that kept him in regular contact with the Catholic hierarchy in a region of the world that still counts the most Catholics.

Although he kept a low profile in Rome, he was part of one of the most significant reforms undertaken by Francis – three women were added to the voting bloc that decides which bishop nominations to put forward to the pope.

Before his election, it was thought that his comparative youth could count against him because cardinals would not want to elect a pope whose reign could last for two decades or more.

These concerns were evidently dismissed by a majority of cardinal electors, who have given the Catholic Church the first pontiff from the US.

The science behind the smoke that signals selection of new pope

VATICAN CITY – All eyes are on the Sistine Chapel and a chimney installed on the roof that will produce smoke signals at the selection of a pope.

Steeped in Catholic tradition, smoke has been used since at least the early 1900s to signify either a successful election or the need for another vote if no one has reached the required votes.

The smoke is produced from burning the ballots used by the College of Cardinals during a papal conclave, which is tasked with electing the next pope.

According to the Vatican, only cardinals under the age of 80 are eligible to participate in the selection process, and voting can be conducted several times a day.

If no candidate receives a two-thirds majority, the ballots are burned with a chemical mixture that produces black smoke. When a new pope is elected, a different chemical mixture is used to make the smoke appear white.

Smoke is produced because when paper burns, it undergoes what is known as "incomplete combustion."

During incomplete combustion, the amount of available oxygen is insufficient to fully oxidize the fuel, releasing chemicals that make the exhaust visible.

The process is similar to what happens during a wildfire, though on a much smaller scale, where insufficient oxygen prevents full combustion.

According to the U.S. National Park Service, which manages many wildfires, at least 16% oxygen is required in the air for flames to ignite.

Human-made materials such as charcoal and coke burn with minimal smoke due to their production in low-oxygen environments, leaving behind carbon-rich solids.

The Catholic tradition would not be possible if cardinals used charcoal or a similar substance, as that would result in what's known as "complete combustion."

The smoke signals have not always been as black and white as the colors suggest.

In past conclaves, confusion sometimes arose over whether the smoke was white or black, prompting Vatican officials to make enhancements.

Since the 2013 conclave that elected Pope Francis, two stoves have been used in the Sistine Chapel: one to burn the ballots and another to add chemical compounds that enhance the color of the smoke.

"The black smoke was produced by a mixture of potassium perchlorate, sulfur and anthracene, a chemical found in coal tar. The white smoke on the other hand was derived from a mixture of potassium chlorate, lactose, and some pine resin known as Greek pitch," Canada's McGill University detailed in a 2017 explainer.

To further eliminate any doubt about the color of the smoke, bells around St. Peter’s Basilica are rung at the same time as the appearance of white smoke.

Soon after the initial signals, a cardinal appears on the balcony of St. Peter's Basilica and announces the famous words "Habemus Papam" - Latin for "We have a pope."

Sometimes the selection of a pope is not straightforward. The Vatican reports the longest conclave lasted nearly three years, with the shortest only lasting a few hours.