Amundsen-Scott South Pole Station experiences months of darkness. The sun dips below the horizon on March 21, after which follows several weeks of twilight before complete darkness results. Photo taken on June 25, 2009. (National Science Foundation/Jeremy Johnson)

“Show us our butts! Mucawana tribe – Angola. In Soba village, the Muhacaona (Mucawana) tribe, perhaps the best place i have visited. They use cow dung and fat to make this so nice haircut, and love the beads. They asked me to make pictures of their backs... and butts to see on the camera screen if everything was perfect!”. (Photo and comments by Eric Lafforgue)

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)

A brilliant sunset makes for a fun silhouette picture by jumping between sand bars at Shi Shi Beach on the Olympic Peninsula Friday July 17, 2015. (Photo by Bettina Hansen/The Seattle Times)

Elementary school sumo wrestlers compete in the sumo ring during the Wanpaku sumo-wrestling tournament in Tokyo, Japan July 30, 2017. (Photo by Kim Kyung-Hoon/Reuters)

Four actors on horseback dressed in Game of Thrones related costumes carry the Queen's Baton as they make their way way along the Dark Hedges on August 29, 2017 in Antrim, Northern Ireland. The Dark Hedges near Stranocum in County Antrim featured as the King's Road in season two of Game of Thrones and has become a tourist mecca for fans of the television series along with other filming locations in the province. The Queen's Baton Relay is currently on a tour of the United Kingdom as it makes its way around Europe in preparation for the 2018 Commonwealth Games in Australia. (Photo by Charles McQuillan/Getty Images)

Bride Duangreuthai Amnuayweroj and groom Kasemsak Jiranantiporn fly while attached to cables during a wedding ceremony ahead of Valentine's Day at a resort in Ratchaburi province, Thailand, February 13, 2016. Four Thai couples took part in the wedding ceremony arranged by the resort. (Photo by Athit Perawongmetha/Reuters)

Some people prepare to catch offerings thrown by Tengger tribe people into the crater of Bromo volcano to in Probolinggo, East Java province, on June 30, 2018, as part of Yadnya Kasada festival which falls on the 14th day of the Kasada month based on the traditional Hindu lunar calendar. (Photo by Juni Kriswanto/AFP Photo)