These powerful images capture the spear-wielding tribes of Papua new Guinea who believe they are possessed with the spirit of the crocodile. They show how the Kangunaman clansmen scar their backs to resemble reptile scales while the Huli Wigmen wear elaborate headdresses to signal they are ready for battle. (Photo by Trevor Cole/Media Drum World)

Dancers perform on stage during Diwali celebrations in Leicester, Britain November 11, 2015. (Photo by Darren Staples/Reuters)

A man prepares tea at a roadside shop on a flooded street in Kolkata, India, August 11, 2016. (Photo by Rupak De Chowdhuri/Reuters)

Women in Chicago being arrested for wearing one piece bathing suits, without the required leg coverings. (Photo by Topical Press Agency/Getty Images). 1922

A model walks down the runway at the 13th China International Young Fashion Designers Contest during China Fashion Week on March 25, 2005 in Beijing, China. (Photo by China Photos/Getty Images)

A girl plays in the Eshash el-Sudan slum in the Dokki neighbourhood of Giza, south of Cairo, Egypt September 2, 2015. Residents of the slum clashed with police in late August, when about 50 ramshackle huts were destroyed and at least 20 people were injured by teargas, local media reported, as authorities attempt to clear the area and rehouse residents. The slum dwellers, some of whom have called Eshash el-Sudan home for 50 years, say there are not enough apartments built nearby to house them. The residents of the slum eke out a living by disposing of rubbish or baking bread. Schooling is too expensive for most of their children, who play with salvaged rubbish amid shacks made out of discarded wood and leather. (Photo by Amr Abdallah Dalsh/Reuters)

On Saturday, September 2, 2017, local Chinese villagers gathered to celebrate a folk festival parade known as “Dog carrying Day” in Jiaobang village, Gedong Town, Jianhe county, Qiandongnan Miao and Dong Autonomous Prefecture, southwest China's Guizhou province. (Photo by Imaginechina/Rex Features/Shutterstock)

These Northern Lights “rainbows” have turned the sky greener than the Earth below. Vitaly Istomin, 26, spent several nights in freezing conditions under the stars in northern Russia’s Khibiny Mountains to capture the aurora’s “rainbows”. (Photo by Vitaly Istomin/Caters News Agency)