Bjorn, aged 5, smiles as he poses with a Owl butterfly during an event to launch the Sensational Butterflies exhibition at the Natural History Museum in London, Britain March 23, 2016. The exhibition opens to the public on March 24 and runs until September 11. (Photo by Dylan Martinez/Reuters)

A Ukrainian serviceman fires a 2S7 Pion self-propelled gun during military exercises near the village of Divychky in Kiev region, Ukraine, October 21, 2016. (Photo by Valentyn Ogirenko/Reuters)

Members of the Indonesian Presidential Security Forces (Paspampres) show their skills during the simulation of a terrorist attack in Jakarta, Indonesia, 29 December 2016. According to reports in local media the Indonesian security forces have already arrested 21 terrorists suspects and fatally shot five of them, who were allegedly planning attacks in the Indonesian capital during the Christmas and New Year's Eve celebrations this year. The presentation was shown on the occasion of a visit by Indonesian President Joko Widodo and a delegation to the Paspampres headquarters in Jakarta. (Photo by Bagus Indahono/EPA)

A relative (L) of Champa Devi, 88, sits next to her body, minutes after her death at Mukti Bhavan (Salvation House) at Varanasi, in the northern Indian state of Uttar Pradesh, June 21, 2014. The city of Varanasi, on the banks of the River Ganges, is widely considered Hinduism's holiest city and many Hindus believe that dying there and having their remains scattered in the Ganges allows their soul to escape a cycle of death and rebirth, attaining “moksha” or salvation. “Mukti Bhavan” or “Salvation House”, is a charity-run hostel that caters for people who wish to come to Varanasi to die. Guests can normally stay up to two weeks after which, if they haven't yet passed away, they are gently asked to leave. (Photo by Danish Siddiqui/Reuters)

Lukas Michul, a member of the “dream walker” group jumps from atop the rugged rocks overlooking the azure waters of Navagio beach, one of the Greece's most renowned leisure spots on the popular tourist island of Zakynthos on June 23, 2014. This is rope jumping – part diving, part rock climbing, with a touch of engineering. The aim of the project is to dream jump in 80 places with most ravishing nature and architecture all over the world .They plan to stage their next leaps at a cave complex in Croatia, a French viaduct, skyscrapers in Las Vegas and Johannesburg, and the Grand Canyon. (Photo by Louisa Gouliamaki/AFP Photo)

A woman walks past a giant Pac-Man in Tokyo's Shinjuku area, Wednesday, August 12, 2015. The three-meter (about nine feet and 10 inches)-tall Pac-Man and other video game characters, made of Lego bricks, were on display to promote the upcoming movie “Pixels”. (Photo by Ken Aragaki/AP Photo)

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)

“Kids of Sapa”. Four little beautiful Hmong girls from Lao Chai Village, near Sapa, Vietnam. (Photo and caption by Felipe Hanower/National Geographic Traveler Photo Contest)