Chief priest Gbenga Saala raises a cutlass to kill a dog during an annual prayer and sacrifice celebration of the iron god Ogun in Abuja, Nigeria, June 23, 2015. Every year worshippers offer a dog as sacrifice to Ogun, a traditional Nigerian deity, in hope of an auspicious year ahead. Taxi drivers, blacksmiths, panel beaters and mechanics – trades that depend on metal for their livelihood – pay homage to Ogun, led by high priest Gbenga Saala. As part of the ceremony, the priest pours the dog’s blood on symbols of these workers’ trade: keys, spanners and other tools piled up in a metal barrel. (Photo by Afolabi Sotunde/Reuters)

Rahma, 19 (L), pictured with her 10-year old brother Fahad on June 21, 2016 in Kano, Nigeria. A teenage girl born without limbs lives her life in a plastic bowl. Rahma Haruna is a bright, happy girl, despite suffering from a mystery condition that stopped her arms and legs developing properly – leaving her practically limbless and in constant pain. The 19-year- old, from Kano, Nigeria, was born a healthy baby but when she turned six months old her growth came to a sudden halt and she stopped hitting key development milestones. Rahma’s family do their best to provide her with a fulfilling life and transport her around the village in a plastic bowl. Rahma said: “They help me a lot. How do they? They give me anything I need”. Rahma died on 25 December 2016. (Photo by Sani Maikatanga/Barcroft Images)

A man runs after he tried to put himself on fire during a protest at a makeshift camp at the Greek-Macedonian border near the village of Idomeni on March 22, 2016. Greece will not be able to start sending refugees back to Turkey from March 20, 2016, the government said, as the country struggles to implement a key deal aimed at easing Europe's migrant crisis. The numbers are daunting: officials said as of Saturday there were 47,500 migrants in Greece, including 8,200 on the islands and 10,500 massed at the Idomeni camp on the Macedonian border. (Photo by Andrej Isakovic/AFP Photo)

A pigeon, known as Siyah Kinifirli, with an approximate market value of 1000 Turkish Lira ($263), bred by 23-year-old Ismail Ozbek, is pictured in Sanliurfa, Turkey, December 23, 2016. As night-time approaches in Sanliurfa, southeastern Turkey, most of the alleyways of the city's old bazaar are emptying out of buyers and vendors, except for one. (Photo by Umit Bektas/Reuters)

Participants take part in the world's first “Pokemon Go” competition in Hong Kong, China, August 6, 2016. The competition began around 2 in the afternoon local time when organizers began announcing the rules on their Facebook page. Contestants had to take screenshots of 12 specific Pokémon in three different districts. Apart from the 12 key Pokémon, participants could also catch designated rare Pokemons which would take off some minutes from their total time. The winner was 21 year old Frankie Chu. The champ took home roughly three hundred and eighty six dollars that he says he will use to pay his school fees. (Photo by Tyrone Siu/Reuters)

Have you ever heard of a psychological phenomenon which lets us easily understand words, even if the order of letters is mixed up, as long as the first and last letters remain in their rightful place? Similarly, the art works of Michael Turner use only two colors to highlight the main futures of well-recognized superheroes, allowing our imagination to create the rest of the picture. The colors used in the pictures weren’t chosen at random. They perfectly reflect the key characteristics of the superheroes that they depict. For example, the picture of Flash uses red and yellow colors, which are exactly the colors of his costume. While the picture of Green Lantern is, you’ve guessed it, green and black. (Photo by Michael Turner)

China has sent its first woman into space on a mission to dock with an orbiting station, the latest step in an ambitious programme to go to the moon and on to Mars.

Photo: China's first female astronaut Liu Yang, waves during a sending off ceremony before she departs for the Shenzhou 9 spacecraft rocket launch pad at the Jiuquan Satellite Launch Center in Jiuquan, China, Saturday, June 16, 2012. China will send its first woman and two other astronauts into space Saturday to work on a temporary space station for about a week, in a key step toward becoming only the third nation to set up a permanent base in orbit. (Photo by Ng Han Guan/AP Photo)

In this photo taken Friday, September 4, 2015, tourists Sarah and John Scott from Worcester, England, take a step back as a male silverback mountain gorilla from the family of mountain gorillas named Amahoro, which means “peace” in the Rwandan language, unexpectedly steps out from the bush to cross their path in the dense forest on the slopes of Mount Bisoke volcano in Volcanoes National Park, northern Rwanda. Deep in Rwanda's steep-sloped forest, increasing numbers of tourists are heading to see the mountain gorillas, a subspecies whose total population is an estimated 900 and who also live in neighboring Uganda and Congo, fueling an industry seen as key to the welfare of the critically endangered species as well as Rwanda's economy. (Photo by Ben Curtis/AP Photo)