Expedition 44 flight engineer and NASA astronaut Scott Kelly seen inside the Cupola, a special module which provides a 360-degree viewing of the Earth and the International Space Station. Kelly is one of two crew members spending an entire year in space. (Photo by Scott Kelly/NASA)

Labourers carry a basket packed with vegetables through a wholesale market in Kolkata, India, February 26, 2016. (Photo by Rupak De Chowdhuri/Reuters)

A man exercises in the early morning on a hilltop overlooking Kabul, Afghanistan March 3, 2016. (Photo by Mohammad Ismail/Reuters)

A man plays to the cameras as racegoers make their way home at the end of Ladies Day the second day of the Aintree Grand National Festival meeting on April 8, 2016 in Aintree, England. Today is Fabulous Friday and Ladies Day of the three-day meeting of the world famous Grand National Festival where fashion and dressing to impress is as important as the racing. (Photo by Christopher Furlong/Getty Images)

An abandoned tank left by Boko Haram, February 20, 2016, seen on the road to Michika, Nigeria – a town formerly occupied by the insurgents. On April 14, 2014, 300 schoolgirls in the Chibok village in Nigeria were kidnapped by the terrorist group, Boko Haram. Two years later, the majority of these girls are still missing. According to the Global Terrorism Index Report 2015, Boko Haram, which operates mainly in Nigeria, has become the most deadly terrorist group in the world. (Photo by Danielle Villasana)

A girl takes pictures after opening ceremony at Shanghai Disney Resort in Shanghai, China, June 16, 2016. (Photo by Aly Song/Reuters)

A biker shows his 12-year-old cat “Chiquinho” – which always rides with him on his motorbike – in Rio de Janeiro, Brazil, on June 19, 2016. (Photo by Yasuyoshi Chiba/AFP Photo)

In this Tuesday, February 28, 2017 photo, 3-month-old Junior Alexis Patino, son of FARC rebel Deisy Garcia, sleeps next to his mother's weapon at a rebel camp in a demobilization zone in La Carmelita, in Colombia's southwestern Putumayo state. Amid the makeshift tents and communal kitchens where Colombia's largest rebel army is preparing to lay down its weapons, a new sound is emerging: the cries of babies. (Photo by Fernando Vergara/AP Photo)