Iranian mourners cover themselves with mud during Ashoura, marking the death anniversary of Imam Hussein, the grandson of Islam's Prophet Muhammad, at the city of Bijar, west of the capital Tehran, Iran, Thursday, November 14, 2013. Hussein, one of Shiite Islam's most beloved saints, was killed in a 7th century battle at Karbala, Iraq. (Photo by Ebrahim Noroozi/AP Photo)

A woman wiper her eyes as she waits to pay her respects before the statues of late North Korean leaders Kim Il Sung and Kim Jong Il, as part of celebrations marking the anniversary of the birth of Kim Il Sung, known as the “Day of the Sun”, on Mansu hill in Pyongyang on April 15, 2019. (Photo by Ed Jones/AFP Photo)

A former paratrooper demonstrates his strength and skills while lifting a chair during the celebrations for the Paratroopers Day at the Central park in the Siberian city of Krasnoyarsk, Russia, August 2, 2015. Paratroopers are an elite unit of the Soviet Army, and everyone in the country recognize their blue berets. (Photo by Ilya Naymushin/Reuters)

Vernon Yates, founder of Wildlife Rescue and Rehabilitation, lays his hands on Ty, a 400-pound tiger, as staff prepare to surgically extract a 4-pound hairball from the big cat, in Clearwater, Florida, on May 22, 2013. Ty is cared for by Wildlife Rescue and Rehabilitation in Seminole. The non-profit animal rescue group mainly serves by assisting Florida law enforcement with animals that have been seized. (Photo by James Judge/Courtesy BluePearl Veterinary Partners)

Angel Paz, dressed as a calavera, waits with family for the start of the Gran Procession of the Catrinas, to mark the upcoming Day of the Dead holiday, in Mexico City, Sunday, October 23 2016. (Photo by Anita Baca/AP Photo)

A picture taken on July 14, 2014 from a Boeing C135 refueling tanker shows two French Rafale fighter planes, flying over the French capital during the annual Bastille Day military parade on the Champs-Elysees in Paris. France has issued an unprecedented invitation to all 72 countries involved in World War I to take part in its annual Bastille Day military parade. (Photo by Franck Pennant/AFP Photo)

A boy jumps over a puddle of water on the outskirts of Havana, Cuba March 21, 2016. (Photo by Ueslei Marcelino/Reuters)

A new book published by the UK Natural History Museum showcases some of the most memorable underwater photographs taken over the last few decades in its annual wildlife photographer of the year competition. Here: Giant gathering by Tony Wu. “The first indication that something extraordinary was going on were the blows, huge numbers of them – the exhalations of huge numbers of whales. Entering the water, the photographer witnessed an extraordinary scene”. (Photo by Tony Wu/Unforgettable Underwater Photography/NHM)