Construction continues on One World Trade Center (TALLEST BUILDING AT LOWER LEFT) as the memorial footprints of the twin towers are seen (BOTTOM C) on August 12, 2011 in New York City. Upon completion, One World Trade Center will be New York's tallest skyscraper, topping out at a symbolic 1,776 feet, with 3 million square feet of office space. More than 2,700 people were killed when al-Qaeda terrorists hijacked U.S. passenger jets and flew them into the twin towers of the World Trade Center on September 11, 2001. Nearly ten years after the crippling attacks on Lower Manhattan, business, tourism and new construction like One World Trade Center have rejuvenated the formerly devastated cityscape.(Photo by Mario Tama/Getty Images)

A model of the New Horizons spacecraft is seen at a live television program on NASA television celebrating the spacecraft's closest proximity to Pluto, at Johns Hopkins University Applied Physics Laboratory, site of the mission operations center, in Laurel, Maryland, USA, 14 July 2015. At approximately 7:49 am ET (11:49 am GMT), 14 July, New Horizons was scheduled to be as close to Pluto as the spacecraft will get; about 7,800 miles (12,500 kilometers) above the surface, following a journey of more than nine years and three billion miles. This is the first mission to the Pluto System and the Kuiper Belt. (Photo by Michael Reynolds/EPA)

An Emperor Tamarin monkey, native to the Amazon rainforest, experiences its new home in the living rainforest enclosure at ZSL London Zoo on March 25, 2010 in London, England. Entitled “Rainforest Life” the large temperature and humidity controlled bio-dome is home to free-roaming monkeys, sloths, tree anteaters and tropical birds. The exhibit, which is opening in the International Year of Biodiversity, will be open to the public from March 27, 2010. (Photo by Oli Scarff/Getty Images)

Men dressed as Vikings lead the torchlight procession as it makes its way along Princess Street for the start of the New Year celebrations December 30, 2011 in Edinburgh, Scotland. Thousands of people joined in the torchlight procession, which is followed by the burning of a Viking long ship, to mark the start of Edinburgh's Hogmanay celebrations. (Photo by Jeff J. Mitchell/Getty Images)

Toby, an 11-year-old German shepherd-husky mix, can hold almost anything on his head that his owner, Pat Langner, can think up, including balls, Christmas trees, and even the ingredients for a peanut butter and jelly sandwich. He also shows remarkable self-restraint by not immediately gobbling down the food that his owner gives him to balance. Here: Toby balances halloween decorations on his head. (Photo by Pat Langer/Caters News Agency)

A UFO enthusiast who found himself locked in the iconic Roswell museum has shared the pictures he took with aliens to pass the time. Chris Burton, from the U.K., had dreamed of visiting Roswell, N.M., since he was a child but was stunned when he found himself locked in the International UFO Museum and Research Center during a recent trip. The 42-year-old used the unique opportunity to get interactive with the usually out of bounds exhibits and set up some funny snaps with the extraterrestrials – posing for a beer with one alien and taking a nap with another. (Photo by Chris Burton/Caters News Agency)

A loved-up couple have captured the moments they shared a dip-kiss in different locations around the world. Rob, 34, and Joli Switzer, 33, from Maryland, embark on a minimum of four international holidays per year to ensure that they get their unique dip-kiss photograph. Here: Rob Switzer 34 proposed to Joli 33 whilst they were on holiday in Moscow, Russia. (Photo by Dipkiss Travels/Caters News Agency)

Daisuke Nagasawa, 49, has spent the past few years taking his two faithful cats, Daikichi and Fuku-Chan, around the world with him. Here: Daisuke Nagasawa travels nationally and internationally with his beautiful kitties Fuku-Chan and Daikichi. The two pose under the iconic Japanese cherry blossoms. (Photo by Daisuke Nagasawa/Caters News Agency)