Starting on Monday, August 12, Perseid meteors will streak across the summer sky for a couple of nights, offering casual stargazers and serious nighttime photographers a chance to capture a glimpse of the annual meteor shower. Photo: Photographer David Kingham created this composite image from 23 photos on August 12, 2012. (Photo by David Kingham)

U.S. soldiers from the 3rd Cavalry Regiment take part in an artillery exercise on forward operating base Gamberi in the Laghman province of Afghanistan December 24, 2014. (Photo by Lucas Jackson/Reuters)

Teachers carry children away from Briarwood Elementary school after the tornado destroyed the school in south Oklahoma City. (Photo by Paul Hellstern/The Oklahoman)

A fighting bull loses its balance during the third day of the San Fermin running-of-the-bulls on July 8, 2011 in Pamplona, Spain. Pamplona's famous Fiesta de San Fermin, which involves the running of the bulls through the historic heart of Pamplona for eight days starting July 7th, was made famous by the 1926 novel of U.S. writer Ernest Hemmingway called “The Sun Also Rises”. (Photo by Denis Doyle/Getty Images)

Two terrified occupants of a Volkswagen Polo found themselves in the wrong place at the wrong time as the giant animal stooped down to rub itself against the vehicle's roof and bonnet. The incredible scene was captured by field guide and lodge manager Armand Grobler, 21, at Pilanesburg National Park in South Africa. (Photo by Armand Grobler/Barcroft Media)

The Jade Belt Bridge, also known as the Camel's Back Bridge, is an 18th-century pedestrian Moon bridge located on the grounds of the Summer Palace in Beijing, China. It is famous for its distinctive tall thin single arch.

People are reflected in a shop window as they walk along a street in a shopping district in Tokyo, Japan June 25, 2015. (Photo by Thomas Peter/Reuters)

Lightning strikes during a storm over the promenade of Palma de Mallorca, Balearics, Spain, on November 4, 2017. Mallorca and Menorca were in yellow alert because of heavy rain and violent winds. (Photo by Cati Cladera/EPA/EFE)