Iranian Kurdish female members of the Freedom Party of Kurdistan (PAK) hold a position on November 6, 2016 in an area near the town of Bashiqa, some 25 kilometres north east of Mosul, during an operation against Islamic State (IS) group jihadists to retake the main hub city. (Photo by Safin Hamed/AFP Photo)

A villager pours pesticide from a bucket as Mount Sinabung spews ash at Kebayaken village in Karo district, Indonesia's North Sumatra province, on December 4, 2013. The country has ordered the evacuation of 15,000 residents near the active volcano. (Photo by Roni Bintang/Reuters)

A tourist take a photograph of a sulphur lake in the Danakil Depression on January 23, 2017 near Dallol, Ethiopia. The depression lies 100 metres below sea level and is one of the hottest and most inhospitable places on Earth. Despite the gruelling conditions, Ethiopians continue a centuries old industry of mining salt from the ground by hand in temperatures that average 34.5 degrees centigrade but have risen to over 50 degrees. (Photo by Carl Court/Getty Images)

“The Lockheed Martin X-33 is an unmanned, sub-scale technology demonstrator suborbital spaceplane developed in the 1990s under the U.S. government-funded Space Launch Initiative program”. – Wikipedia

Photo: An Artist's Rendering Shows How Nasa's X-33 Technology Demonstrator, A Cost-Cutting Fully Reusable Single-Stage-To-Orbit Space Vehicle, Will Look Upon Completion. The 67 Foot-Long, 278,600 Pound, Twin Engine Space Vehicle, Capable Of Reaching Speeds In Excess Of Mach 15, Will Lead To The Construction Of A 127 Foot-Long, 2,186,000 Pound Version With Seven Engines And A 50,000 Pound Payload Capacity Called The “Venturestar”. (Photo By Nasa/Getty Images)

Bill Moreau watches as the Black Forest fire burns near his house near Black Forest Road Tuesday afternoon, June 11, 2013, near Colorado Springs, Colo. The Black Forest Fire was one of at least three significant wildfires burning in Colorado amid gusty winds and record-breaking hot, dry weather. (Photo by Christian Murdock/AP Photo/The Colorado Springs Gazette)

A member of the “Ladies in White” dissident group shouts as she is carried away by police officers after they broke up a regular march of the group, detaining about 50 people, hours before U.S. President Barack Obama arrives for a historic visit, in Havana, Cuba March 20, 2016. (Photo by Ueslei Marcelino/Reuters)

“Cheddar Gorge is a limestone gorge in the Mendip Hills, near the village of Cheddar in Somerset, England. The gorge is the site of the Cheddar show caves, where Britain's oldest complete human skeleton, Cheddar Man, estimated to be 9,000 years old, was found in 1903. Older remains from the Upper Late Palaeolithic era (12,000–13,000 years ago) have been found. The caves, produced by the activity of an underground river, contain stalactites and stalagmites”. – Wikipedia

Photo: A general view of Cheddar Gorge is seen on March 22, 2012 in Cheddar, England. With only a few months to go until the opening ceremony of the London 2012 Olympic games, Britain's tourist industry is hoping to benefit from the influx of athletes, officials and visitors. (Photo by Matt Cardy/Getty Images)

A man carries his wife on his back as they make their way with their luggage along a flooded tunnel to catch their train, after heavy rainfall hit Jinhua, Zhejiang province, China, July 21, 2015. (Photo by Reuters/China Daily)