Singer Jason Derulo performs during his Flash Mob with Knicks City Dancers outside of Madison Square Garden on September 28, 2011 in New York City. (Photo by Mike Coppola/Getty Images)

This image provided by NASA shows parts of Europe and Africa very easily recognizable in this night time image shot by one of the Expedition 25 crew members aboard the International Space Station flying 220 miles above Earth on Thursday October 28, 2010. The view “looks” northward over Sicily and the “boot” of Italy, with the Mediterranean Sea representing most of the visible water in the view and the Adriatic Sea to the right of center. Tunisia is partially visible at left. Part of a docked Russian spacecraft and other components of the ISS are in the foreground. (Photo by AP Photo/NASA)

In this April 28, 2014 file photo, a woman throws a rock and a bag at police blocking her from getting home in the Huepetuhe district of the Madre de Dios region of Peru. Security forces began destroying illegal gold mining machinery in Peru's southeastern jungle region of Madre de Dios, as authorities began enforcing a ban on illegal mining. (Photo by Rodrigo Abd/AP Photo)

A picture made available in 01 July 2016 shows a 16-meter-long and 6.5-meter-high model of a Spinosaurus installed by employees of the dinosaur park in Muenchenhagen in the region of Hannover, Germany, 28 June 2016. The model is considered the only replica of this dinosaur species worldwide. The outdoor museum at Lake Steinhude shows more than 230 true-to-scale replica of dinosaurs. (Photo by Holger Hollemann/EPA)

A man holds a metal bar as a weapon during a training day for former soldiers and volunteers train in a makeshift camp in the outskirts of Port-au-Prince, Haiti, October 28, 2015. Haiti disbanded its abusive armed forces two decades ago but uniformed veterans and young recruits are resurfacing to add another destabilising factor to the volatile Caribbean nation already dealing with a political vacuum. (Photo by Andres Martinez Casares/Reuters)

Two brothers have built a human catapult to fly into a lake. Johannes Schrieber, 26, and his brother Daniel, 28, from Frankfurt, Germany built the wooden contraption, which can fire people five metres into the sky and 12 metres away. The brothers raised more than £700 through crowdfunding to buy the materials, with every penny well spent as nobody has died yet! (Photo by Caters News)

A Maasai man in ceremonial dress poses for visitors to take photographs of him in front of one of around a dozen pyres of ivory, in Nairobi National Park, Kenya Thursday, April 28, 2016. The Kenya Wildlife Service (KWS) has stacked 105 tons of ivory consisting of 16,000 tusks, and 1 ton of rhino horn, from stockpiles around the country, in preparation for it to be torched on Saturday to encourage global efforts to help stop the poaching of elephants and rhinos. (Photo by Ben Curtis/AP Photo)

A visitor looks at portraits of Mao Zedong amid his statues on display at a wholesale souvenir store in Shaoshan, Hunan Province in central China, 28 April 2016. Shaoshan is the hometown of former Communist leader Mao Zedong, popularly known as Chairman Mao. Thousands of visitors descend on this small Chinese town burrowed in the hills of Central China's Hunan province to pay homage to the “Great Helmsman” everyday. It is one of the core sites of the “Red Tourism” industry, where communist party cadres and ordinary Chinese tourists alike seek to relive the experiences and rekindle the spirit of the revolutionaries. (Photo by How Hwee Young/EPA)