Demonstrators take part in a protest against U.S. President Donald Trump in Glasgow, Britain February 20, 2017. (Photo by Russell Cheyne/Reuters)

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)

Abbas (1944 – 25 April 2018) was an Iranian photographer known for his photojournalism in Biafra, Vietnam and South Africa in the 1970s, and for his extensive essays on religions in later years. He was a member of Sipa from 1971 to 1973, a member of Gamma from 1974 to 1980, and joined Magnum Photos in 1981. Here: Kuwait, 1991. (Photo by Abbas Attar/Magnum Photos)

Urban photographer Roman Robroek spent five years scouring the continent for the grandest examples of forgotten architectural beauty. Here: Watch your step on this Polish spiral staircase. (Photo by Roman Robroek/South West News Service)

A photographer has created a series of paw-traits of hungry dogs pulling hilarious faces as they try and catch treats. Using a unique technique, the shots are captured at the exact moment the adorable pooches attempt to catch an airborne piece of food. The dogs appear surprised, happy, sad, confused – and sometimes even so blasé they miss the treat entirely. The images were taken by Christian Vieler, a photographer from Waltrop, Germany. Here: A labrador retriever. (Photo by Christian Vieler/Caters News)

A reveller (R), dressed as “Diablos de Luzon” (Luzon Devils), stands next to a person dressed as a “Mascaritas” during carnival celebrations in the village of Luzon, Spain, February 6, 2016. The “Diablos” cover themselves in a mixture of soot and oil and adorn their heads with black-stained bull horns as they parade throughout the village with cowbells clanging around their waists to expel the evil spirits. (Photo by Sergio Perez/Reuters)

SpaceX’s Dragon spacecraft, March 6, 2014. SpaceX's Falcon 9 rocket and Dragon spacecraft launched from Launch Complex 40 at the Cape Canaveral Air Force Station, Florida, for their third official Commercial Resupply (CRS) mission to the orbiting lab on April 18, 2014. Dragon returned to Earth with a parachute-assisted splashdown off the coast of southern California on May 14, 2014. Dragon is the only operational spacecraft capable of returning a significant amount of supplies back to Earth, including experiments. (Photo by Ron Lin/SpaceX Photos)

The NASA Extreme Environment Mission Operations (NEEMO) 21 mission began on July 21 as an international crew of aquanauts splashed down to the undersea Aquarius Reef Base, located 62 feet below the surface of the Atlantic Ocean in the Florida Keys National Marine Sanctuary. The NEEMO 21 crew will perform research both inside and outside the habitat during a 16-day simulated space mission. During simulated spacewalks carried out underwater, they will evaluate tools and mission operation techniques that could be used in future space missions, including journeys to Mars. (Photo by Karl Shreeves/NASA)