A woman looks out of a dusty window after boarding a bus to be transported to see the casket of Nelson Mandela at the Union Buildings in Pretoria, South Africa, Wednesday December 11, 2013. On Thursday, December 5, 2013, Mandela died at the age of 95. (Photo by Markus Schreiber/AP Photo)

Katjinga, a Rhodesian ridgeback dog who lives on a 20-acre farm in Germany, adopted an abandoned pot-bellied piglet in August 2009. The tiny black piglet, named Paulinchen, had been so small at birth that her mother likely overlooked it. Katjinga's owner, Roland Adam, found the piglet alone and cold and brought it to his 8-year-old dog. (Photo by Fame Pictures)

Finding just the right spot above the clouds at Camp 1 on Ama Dablam, Danuru Sherpa uses his iPhone to catch up with friends and family. Even at 18,500 feet (5,654 meters), climbers here can check their email and other dispatches from the world below. (Photo by Aaron Huey/National Geographic)

People take part in a Halloween street party at Lan Kwai Fong on October 31, 2016 in Hong Kong. Halloween, a contraction of All Hallows' Evening, falls on the day before All Saints' Day on November 1, a holiday when Christians remember their deceased loved ones. (Photo by Lam Yik Fei/Getty Images)

Joel said documenting the Kazakh nomad summer migration was really an epic journey – a time travel journey – and at the same time was possible to get an understanding of how the balance of nature is still possible in Altai Mountains, Mongolia, June 2015. (Photo by Joel Santos/Barcroft Images)

(L-R) Jade Chapman, Maryam Maquillage, Mariah Carey, Laura Lee and Arika Sato attend M.A.C Cosmetics Mariah Carey Beauty Icon Launch at Baccarat Hotel on December 3, 2016 in New York City. (Photo by Theo Wargo/Getty Images for M.A.C)

A young Matachin dancer sits on a the side during the annual pilgrimage in honor of Mexico's patron saint the Virgin of Guadalupe in Ciudad Juarez, Mexico, December 12, 2016. (Photo by Jose Luis Gonzalez/Reuters)

A Rohingya migrant woman, who arrived in Indonesia by boat, carries a bottle of drinking water inside a temporary compound for refugees in Kuala Cangkoi village in Lhoksukon, Indonesia's Aceh Province May 17, 2015. (Photo by Reuters/Beawiharta)