An East German civilian (L) shows an East German customs officer the contents of his Trabant (auto) at checkpoint Potsdamer Platz in East Berlin in this November 24, 1989 file picture, as East Germany enforcing stringent customs controls to avoid smuggling. (Photo by Reuters)

Lightning streaks across the sky as lava flows from a volcano in Eyjafjallajokul April 17, 2010. (Photo by Lucas Jackson/Reuters)

In this August 28, 1963 file photo, the top of the Washington Monument and part of a U.S. flag are reflected in the sunglasses of Austin Clinton Brown, 9, of Gainesville, Ga., as he poses at the Capitol where he joins others in the March on Washington. (Photo by AFP Photo)

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)

Lightning strikes during a storm over the Ionian Sea in Calabria, Italy on June 27, 2016. (Photo by Alfonso Di Vincenzo/Pacific Press/Rex Features)

Brad Snead walks past melting ice on the Cook Inlet beach, Saturday, March 26, 2011, in Kenai, Alaska, while looking for agates. (AP Photo/Peninsula Clarion, M. Scott Moon)

These images give a rare insight into the life of a 19th Century Indian Maharajah. Maharajah Ram Singh ruled in the famous pink city of Jaipur between 1835 and 1880, and was also a keen photographer. Here: Full portrait of a woman in the harem in the royal palace of Jaipur, India, 1857 – 1865. (Photo by Maharaja Ram Singh III/Alinari via Getty Images)

A picture made available on 08 July 2015 showsa lightning strikes during a heavy storm over Poznan in the night of 07 July 2015. Severe storms passed last night over Poland causing lots of damages to buildings, trees, electricity and railway tractions. (Photo by Lukasz Ogrodowczyk/EPA)