An Afghan girl carries water on her back as she climbs a hill in Kabul, Afghanistan February 20, 2017. A growing population is straining water supplies in Afghanistan's capital, forcing those who can afford it to dig unregulated wells ever deeper to tap a falling water table. Finding water in arid Afghanistan is virtually always a challenge, but a drop in the groundwater level in Kabul caused by overuse and drought is making it even more difficult for residents, especially the poor. (Photo by Omar Sobhani/Reuters)

Lindsay Heimbach goes airborne while sledding down a hill on Mt. Lemmon December 27, 2008. (Photo by James Gregg/Arizona Daily Star)

Members of security forces secure Tahrir Square in Cairo, Egypt, November 11, 2016. Egypt imposed a big security clampdown in its cities on Friday as mass demonstrations called to protest against austerity measures failed to take place. Riot police and armored vehicles filled the otherwise empty streets of central Cairo, but most people stayed at home. (Photo by Mohamed Abd El Ghany/Reuters)

A hot air balloon floats past an almost full rising moon on a warm fall evening near Encinitas, California October 5, 2014. (Photo by Mike Blake/Reuters)

Astronaut Edward H. White II, pilot for the Gemini-Titan 4 (GT-4) spaceflight, floats in the zero-gravity of space during the third revolution of the GT-4 spacecraft on June 3, 1965. White wears a specially designed spacesuit. His face is shaded by a gold-plated visor to protect him from unfiltered rays of the sun. In his right hand he carries a Hand-Held Self-Maneuvering Unit (HHSMU) that gives him control over his movements in space. White also wears an emergency oxygen chest pack; and he carries a camera mounted on the HHSMU for taking pictures of the sky, Earth and the GT-4 spacecraft. He is secured to the spacecraft by a 25-feet umbilical line and a 23-feet tether line. Both lines are wrapped together in gold tape to form one cord. Astronaut James A. McDivitt, command pilot, remained inside the spacecraft during the extravehicular activity (EVA). Astronaut White died in the Apollo/Saturn 204 fire at Cape Kennedy on January 27, 1967. (Photo by NASA)

While most people head for cover at the first sign of a storm, this man runs straight toward it. Storm chaser and father of three Mike Olbinski is addicted to photographing extreme weather and regularly takes on tornadoes and supercell thunderstorms in a bid to capture extraordinary images. The photographer, from Phoenix, often travels hundreds of miles a day to reach the eye of a storm. He first became hooked on the unusual hobby almost a decade ago, following the birth of his daughter. Here: A stunning monsoon sunset coupled with intense lightning creating an amazing scene on August 26, 2017. (Photo by Mike Olbinski/Caters News Agency)

A boy bursts a soap-bubble at Gorky Park in Moscow on July 19, 2017. (Photo by Mladen Antonov/AFP Photo)

NASA astronaut Reid Wiseman and European Space Agency astronaut Alexander Gerst (not shown) works outside the space station's Quest airlock in the first of three spacewalks for the Expedition 41 crew aboard the International Space Station in this NASA image released October 8, 2014. (Photo by Reuters/NASA)