Planes land in fog at Heathrow Airport, west London, as heavy fog covers a many parts of the south east, on April 1, 2014. (Photo by Steve Parsons/PA Wire)

Breitling Wingwalker Freya Paterson, from Liverpool, UK, flies above Kuwait City's iconic Water Towers with pilots David Barrell and Martyn Carrington, on March 6, 2014. The team loop and roll up to 160 mph enduring G-forces of 4-5g. Crowds are expected to line the Kuwaiti coastline to catch a glimpse of the Wingwalking team on Saturday, March 8, 2014, to mark the opening of the first dedicated boutique in the city for the prestigious watch brand. (Photo by Katsuhiko Tokunaga/Breitling)

MTV “Ex On The Beach” star Charlotte Dawson and Big Brother star Sam Giffen (not pictured) having fun on a night out in Manchester, England after leaving neighbourhood restaurant on September 8, 2016. (Photo by XposurePhotos.com)

Children, wearing red neckerchiefs, a symbol of the Pioneer Organization, salute during a ceremony for the inauguration of 18 new members at a local school in the southern settlement of Kazminskoye in Stavropol region, Russia, November 19, 2015. Early pro-communist youth movements, which appeared in Russia after the 1917 Bolshevik revolution, were reformed into the Pioneer Organization of the Soviet Union. While the organization lost its dominance among students in post-Soviet Russia, some educational institutions and families still carry on this tradition. (Photo by Eduard Korniyenko/Reuters)

The US Navy Blue Angels numbers 5 and 6 fly below Sean Tucker (above) as he pilots the Oracle Challenger III over San Francisco, California as part of a practice run for Fleet Week on October 6, 2016. (Photo by Josh Edelson/AFP Photo)

US President George W. Bush (R) and Russian President Vladimir Putin wave as the two presidents go for a ride in Putin's 1956 Volga before dinner 08 May 2005 at the his residence outside of Moscow. Bush hailed Russia's “bravery and sacrifice” in defeating Nazism, as he met Putin ahead of ceremonies marking the 60th anniversary of the end of World War II. Bush, who the previous day criticized the decades-long Soviet occupation of central Europe, said he was looking forward to the 09 May ceremony on Moscow's Red Square, to be attended by over 50 national leaders. (Photo by Tim Sloan/AFP Photo)

HRP-4C, a five-foot humanoid robot developed at Japan's National Institute of Advanced Industrial Science and Technology, sings and dances with performers at the Digital Contents Expo in Tokyo on October 17, 2010. The robot runs entertainment software called Choreonoid, a name formed from the words “choreograph” and “humanoid”. (Yoshikazu Tsuno/AFP)

Two Inuit children at Point Barrow, Alaska, holding the tusks of a large walrus, probably killed for food, circa 1930. (Photo by General Photographic Agency/Getty Images)