US marines watch the mushroom cloud from an atomic explosion rise above the Yucca flats, Nevada during a US nuclear weapons test. (Photo by Keystone/Getty Images). USA, 1945

A dog named Yoda looks on during the 23rd Annual World's Ugliest Dog Contest at the Sonoma-Marin County Fair on June 24, 2011 in Petaluma, California. Yoda won the $1,000 top prize as the world's ugliest dog. (Photo by Justin Sullivan/Getty Images)

Emperor penguins gathered together to keep their chicks warm in these pictures. Marine scientist Frederique Oliver snapped the protective parents in Antarctica as they huddled against the huge winds.The adorable birds have to battle temperatures on -20 degrees Celsius as well as winds of up to 40 knots on the ice. (Photo by Frederique Oliver/Caters News)

Ugly dog contestants Sweepee Rambo and owner Jason Wurtz celebrate in winning the 2016 World's Ugliest Dog Contest at the Sonoma-Marin Fair in Petaluma, California, USA, 24 June 2016. (Photo by Peter Dasilva/EPA)

A marine rescue worker from Sea World works in a joint attempt with his colleagues to help a juvenile humpback whale stranded at Palm Beach on the Gold Coast, in Queensland July 9, 2014. (Photo by Jason O'Brien/Reuters)

A marine aims an RPG-7, a portable rocket- propelled grenade launcher, during military exercises conducted by the Russian Pacific Fleet' s naval infantry unit at the Bamburovo firing range on February 2, 2017. The drills are a part of preparations for the Suvorov Attack and Sniper Line army competitions. (Photo by Yuri Smityuk/TASS)

A ballet dancer attends a photo shooting as activists from the environmentalist group Greenpeace unfurl a giant banner on the Eiffel Tower which reads “Liberty, Equality, Fraternity” in a call on French citizens to vote against the National Front (FN) presidential candidate Marine Le Pen, in Paris, France May 5, 2017. (Photo by Gonzalo Fuentes/Reuters)

A man passes a poster depicting French presidential election candidate for the far-right Front National (FN) party Marine Le Pen with the face of U.S. President Donald Trump reading “Do not Trump yourself. Choose France. Vote!” on May 5, 2017 in Paris. (Photo by Joel Saget/AFP Photo)