Two of 20 skulls to be taken possession of by a delegation from Namibia stand on display at a ceremony at Charite hospital on September 30, 2011 in Berlin, Germany. The skulls are from Herero and Nama tribespeople taken by German colonial forces between 1904 and 1908, when the Germans violently suppressed an uprising in what was then German Southwest Africa, which is today's Namibia, and in the process killed tens of thousand of Herero and Nama. German scientists at the time took the skulls back to Berlin to demonstrate the racial superiority of Europeans over black Africans. Many Namibians demand a formal apology from the German government. (Photo by Sean Gallup/Getty Images)

A pile of destroyed cars of teachers sits outside Briarwood elementary school in Oklahoma City, Oklahoma May 22, 2013. Rescue workers with sniffer dogs picked through the ruins on Wednesday to ensure no survivors remained buried after a deadly tornado left thousands homeless and trying to salvage what was left of their belongings. Curvature of horizon in the photo is due to an ultra-wide angle lens. (Photo by Rick Wilking/Reuters)

Space Shuttle Atlantis lands at the Kennedy Space Center July 21, 2011 in Cape Canaveral, Florida. The landing brings to a close the 30-year era of the space shuttle program that began in 1981, and has included 135 missions. (Photo by Bill Ingalls/NASA via Getty Images)

Christopher Tubbs embraces his wife Sarah after arriving home during the homecoming of the USS Enterprise at the Norfolk Naval Station July 15, 2011 in Norfolk, Virginia. In its 184 days away from Norfolk, the USS Enterprise cruised nearly 60,000 miles while supporting operations in Afghanistan and Iraq. (Photo by Win McNamee/Getty Images)

A minaret, that was damaged during fighting between Islamic State jihadists and government forces, is seen in Ben Guerdane, near the Libyan border, Tunisia April 10, 2016. After a U.S. air strike killed a Tunisian jihadist commander in western Libya in late February, dozens of Islamic State fighters sneaked across the border into Tunisia and attacked an army barracks and police bases in the town of Ben Guerdane. (Photo by Zohra Bensemra/Reuters)

These spectacular pictures show the incredible moment a rare natural phenomenon happens in the night sky. Red sprite lightning lasts only a millisecond and takes place high above a tunderstorm cloud.The breathtaking flashes of light are caused by huge electrical discharges of lightning in the sky. Marko Korosec, 32, was lucky enough to catch these sprites on camera after months of trying. Mr Korosec, from Sezana in Slovenia, took the shots whilst he was following storms in Vivaro, Italy. (Photo by Marko Korosec/Solent News/SIPA Press)

A worker inspects the Christ the Redeemer statue which was damaged during lightning storms in Rio de Janeiro January 21, 2014. (Photo by Severino Silva/Reuters/Agência o Dia)

An installation entitled “Take my lightning but don't steal my thunder” by British artist Alex Chinneck stands in Covent Garden on October 2, 2014 in London, England. The installation is intended to cast the illusion that a 40-foot section of the Covent Garden's 184-year old market building is floating. “Take my lightning but don't steal my thunder” will be on display from 2nd to 24th October 2014. (Photo by Rob Stothard/Getty Images)