ESA astronaut Samantha Cristoforetti on the International Space Station 3 February 2015 during her Futura mission. Samantha is living and working on the Station as part of the Expedition 42 crew. Picture released on February 10, 2015. (Photo by ESA/NASA)

An young Indian Jain devotee dressed as Lord Krishna participates in a religious rally organised on the occasion of Mahavir Jayanti in Kolkata on April 2, 2015. The most important religious holiday in Jainism, Mahavir Jayanti celebrates the birth of Mahavira, the last Tirthankara, which is generally accepted as 599 BCE. (Photo by Dibyangshu Sarkar/AFP Photo)

In this April 2, 2015 photo, dog owner Laura Aquilina strolls with her two year old Rottweiler Brutus, who was recently fitted with prosthetics on all four paws, and is currently learning to use them, near Aquilina's home in Loveland, Colo. Brutus lost all four paws to frostbite as a puppy while under care of a breeder, and Aquilina began caring for him about a year ago. (Photo by Brennan Linsley/AP Photo)

In this photograph taken on April 1, 2015, an Indonesian resident and child walk away from an abandoned school building as Mount Sinabung erupts in Karo district on the Indonesian island of Sumatra. According to authorities about 3,500 people were displaced after the February 2014 eruption of Mount Sinabung volcano and many are still living in evacuation centers as the volcano remains active. (Photo by Sutanta Aditya/AFP Photo)

Te Matatini Kapa Haka Aotearoa perform the Haka at the Edinburgh Festival Fringe on the Royal Mile on August 14, 2014 in Edinburgh, Scotland. The largest performing arts festival in the world, this years festival hosts more than 3,000 shows in nearly 300 venues across the city. (Photo by Jeff J. Mitchell/Getty Images)

A person dressed as an astronaut walks past a man stopping traffic on a pedestrian crossing outside the Sydney Exhibition Centre September 13, 2014 where the science-fiction convention called “Oz Comic-Con” is currently being held. The two-day convention showcases “pop culture”, and includes appearances by actors from science-fiction movies and television shows. (Photo by David Gray/Reuters)

A picture made available on 17 September 2014 shows extreme athletes resting in hammocks on webbings stretched between rocks during the International Highline Meeting in Monte Piana, near Misurina, in the northern Italian Alps, Italy, 08 September 2014. (Photo by Balazs Mohai/EPA)

Italian disabled dancer Simona Atzori (top) performs, before a special audience with disabled athletes led by Pope Francis, in Paul VI hall at the Vatican October 4, 2014. (Photo by Tony Gentile/Reuters)