Photographers gather to take pictures of pilot Andre Borschberg (C) ahead of the take off of Solar Impulse 2-a solar powered plane- in Nanjing, China, May 31, 2015. The world's largest solar-powered airplane, Solar Impulse 2, took off from eastern China's Nanjing on Sunday to continue its round-the-world voyage. The Swiss-made plane left Nanjing's Lukou International Airport at 2:39 in the early morning, with former fighter pilot Borschberg at the controls alone for the entire 8,200-kilometer flight from Nanjing to Hawaii, the toughest leg of its marathon adventure. (Photo by Reuters/Solar Impulse)

A sailor of the Marshal Shaposhnikov anti-submarine destroyer takes part in the “Vostok-2022” military exercises at the Peter the Great Gulf of the Sea of Japan outside the city of Vladivostok on September 5, 2022. The Vostok 2022 military exercises, involving several Kremlin-friendly countries including China, takes place from September 1-7 across several training grounds in Russia's Far East and in the waters off it. Over 50,000 soldiers and more than 5,000 units of military equipment, including 140 aircraft and 60 ships, are involved in the drills. (Photo by Kirill Kudryavtsev/AFP Photo)

A selection of prizewinning images from the Take a View 2016 photography awards. Here: Finding Gold, taken in Wast Water in Cumbria, which won the Great Britain #OMGB “Home of Amazing Moments” award. (Photo by Mark Gilligan/PA Wire)

School children take shelter under desks during a tsunami simulation drill ahead of World Tsunami Awareness Day at Futaba elementary school in Choshi, Chiba Prefecture, Japan, November 4, 2016. (Photo by Kim Kyung-Hoon/Reuters)

A Belarussian tourist crosses the river as he takes part in “Search and rescue operations – 2016”, a three-day competition, near the village of Priselki, Belarus, November 25, 2016. Photo taken November 25, 2016. (Photo by Vasily Fedosenko/Reuters)

Yussef Saluta (R), 20, an Israeli Arab soldier from the Desert Reconnaissance battalion takes part in a drill near Kissufim in southern Israel November 29, 2016. A battalion of soldiers crawls across the desert sand with assault rifles cocked. It's a routine exercise, but these are no ordinary troops – they are Arabs who have chosen to fight for the Jewish state. (Photo by Amir Cohen/Reuters) (Photo by Amir Cohen/Reuters)

Alpine Skiing, FIS Alpine Skiing World Cup, Men's Parallel Giant Slalom, Alta Badia, Italy on December 19, 2016. Hostesses take a bath in a Jacuzzi pool during the race. (Photo by Stefano Rellandini/Reuters)

An Israeli soldier watches as revellers take part in a gay pride parade in Tel Aviv, Israel, June 3, 2016. About 200,000 people from the LGBT community in Israel and abroad attended in Tel Aviv's annual gay pride parade Friday, the largest event of its kind in the Middle East. (Photo by Baz Ratner/Reuters)