A member of the Eton public school O.T.C. (Officers Training Corps) practising shouting out orders during a training session, 20th January 1940. (Photo by Hulton Archive/Getty Images)
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)
A model walks the runway during the Vivienne Westwood show as part of the Paris Fashion Week Womenswear Fall/Winter 2018/2019 on March 3, 2018 in Paris, France. (Photo by Patrick Kovarik/WireImage)
A passenger aircraft passes over a residential house as it prepares to land at London Heathrow Airport in west London on October 17, 2016. Britain's government is considering whether to approve a third runway at Heathrow or expand air capacity in southeast England at another airport such as London Gatwick. (Photo by Daniel Leal-Olivas/AFP Photo)
The damaged battleship USS California, listing to port after being hit by Japanese aerial torpedoes and bombs, is seen off Ford Island during the attack on Pearl Harbor, Hawaii, U.S. December 7, 1941. The 75th anniversary of the attack, which brought the United States into World War Two, is marked on December 7, 2016. (Photo by Reuters/U.S. Navy/National Archives)
A spotted owlet appears to be playing peek-a-boo near Rancharda Lake in Ahmedabad, India on February 9, 2016. The species is common across the Indian subcontinent. (Photo by Caters News Agency)