A couple takes a selfie as Hoa Binh hydroelectric power plant opens the flood gates after a heavy rainfall caused by Talas typhoon in Hoa Binh province, outside Hanoi, Vietnam July 20, 2017. (Photo by Reuters/Kham)

National Geographic photographer Steve Winter has spent most of his adult life shooting wild cats. Photo: A 14-month-old cub, cooling off in a pond, is riveted by a deer that appeared near the shore. Tigers are powerful swimmers; they can easily cross rivers four to five miles wide and have been known to swim distances of up to 18 miles. (Photo by Steve Winter/National Geographic)

Five-year-old Julian Becker and his 165 pound pet Newfoundland Max have been best buds around all their lives. To commemorate the friendship and to keep Julian's father, a Naval officer who is often away, in the loop, Julian's mom Stasha began taking photos. Photo: Hats off (or on) to Julian for sharing his blanket with his good buddy. Not that the furry beast needs it... (Photo by Stasha Becker/Rex Features)

The lightest material ever made has been produced by a team of scientists in China, a Chinese university announced.

A man poses standing on a rock looking at the aurora borealis, or northern lights, illuminating the night sky at Embleton Bay in Northumberland, England, on February 27, 2014. The northern lights is a fantastical natural light display with fast moving light effects caused by particles charged by the sun colliding with particles in Earth's upper atmosphere. (Photo by Tom White/PA Wire)

People watch a forest fire in Funchal, Madeira Island, Portugal, 09 August 2016. The fire has led to the evacuation of 400 people. Portugal remains on high alert as a wave of wildfires has swept the country with around 350 isolated fires affecting swathes of the countryside. (Photo by Gregório Cunha/EPA)

A news reporter doing a stand up near a sea wall in Cedar Key, Fla., is covered by an unexpected wave as Hurricane Hermine nears the Florida coast, Thursday, September 1, 2016. Hurricane Hermine gained new strength Thursday evening and roared ever closer to Florida's Gulf Coast, where rough surf began smashing against docks and boathouses and people braced for the first direct hit on the state from a hurricane in over a decade. (Photo by John Raoux/AP Photo)

An explosion occurs following an Israeli air strike on a residential building, amid the Israel-Hamas conflict, in Nuseirat in the central Gaza Strip, on July 20, 2024. (Photo by Omar Naaman/Reuters)