NEW YORK: The Tribute in Light memorial illuminates the New York skyline to mark the 23rd anniversary of the September 11 attacks (Eduardo Munoz/Reuters)

PHILADELPHIA: A countdown clock over debate moderators David Muir and Linsey Davis shows how much time former President Donald Trump has left to answer a question during his presidential debate with Vice President Kamala Harris on Tuesday, September 10 (Michael Le Brecht II/ABC News)

SPACE: This image, made from a SpaceX video, shows Jared Isaacman leading a private spacewalk during the Polaris Dawn mission on Wednesday, September 11. Isaacman was part of the four-person civilian crew that was the first group of non-government astronauts to conduct a spacewalk (SpaceX/AP)

TAICANG: New recruits train at the National Defense Education and Training Center in Taicang, China, on Monday, September 9 (AFP/Getty Images)

PARIS: Colombian athlete Mauricio Valencia sinks his teeth into his gold medal after winning a shot put event at the Paris Paralympics on Saturday, September 7. Valencia had his teeth modified to mimic fangs, he said, in at attempt to change the stigma toward Paralympic athletes (David Ramos/Getty Images)

MEXICO CITY: Protesters try to break into a room in the Mexican Senate as lawmakers weighed a controversial judicial reform in Mexico City on Tuesday, September 10. Protesters broke into the Senate chamber and forced a suspension of the proceedings, but hours later the Senate narrowly passed the reform, under which Mexicans would elect judges at all levels of government by a popular vote (Felix Marquez/AP)

PATTERSON: A trailer park in Patterson, Louisiana, is flooded after Hurricane Francine slammed into the state on Thursday, September 12 (Marco Bello/Reuters)

BARCELONA: A woman puts a Catalonian flag on her balcony in Barcelona, Spain, during the National Day of Catalonia on Wednesday, September 11 (Emilio Morenatti/AP)

AMSTERDAM: Climate activists from the group Extinction Rebellion stage a protest at an entrance of the Rijksmuseum in Amsterdam, Netherlands, on Saturday, September 7. They were protesting against the museum's main sponsor, ING (Dingena Mol/ANP/AFP/Getty Images)

BAZA: A man jumps in the crowd during the Cascamorras festival in Baza, Spain, on Friday, September 6 (Jorge Guerrero/AFP/Getty Images)