Women, wearing traditional “ao dai” dress, pose for a photo next to peach blossom flowers ahead of Vietnamese “Tet” (the lunar new year festival) in a field in Hanoi January 22, 2017. (Photo by Reuters/Kham)

Medic James E. Callahan of Pittsfield, Mass., gives mouth-to-mouth resuscitation to a dying soldier in war zone D, about 50 miles northeast of Saigon, June 17, 1967. Thirty-one men of the 1st Infantry Division were reported killed in the guerrilla ambush, with more than 100 wounded. (Photo by Henri Huet/AP Photo)

A couple takes a selfie as Hoa Binh hydroelectric power plant opens the flood gates after a heavy rainfall caused by Talas typhoon in Hoa Binh province, outside Hanoi, Vietnam July 20, 2017. (Photo by Reuters/Kham)

“Falling Back To Earth” promises to be both spectacular and meditative, and presents a beautiful, thought-provoking vision of our relationship with the earth and with each other. (Photo by Dave Hunt/EPA)

Visitors look over masses of ice formed around the Canadian “Horseshoe” Falls in Niagara Falls, Ontario, Canada, Thursday, February 19, 2015. (Photo by Aaron Lynett/AP Photo/The Canadian Press)

Spanish legionnaires sing an anthem as they carry a statue of the Christ of Mena outside a church during a ceremony before they take part in the “Mena” brotherhood procession in Malaga, southern Spain, March 24, 2016. (Photo by Jon Nazca/Reuters)

Mary Ellen Mark was an American photographer known for her photojournalism / documentary photography, portraiture, and advertising photography. She photographed people who were "away from mainstream society and toward its more interesting, often troubled fringes". Here: Amanda and her cousin Amy, Valdese, North Carolina, 1990. (Photo by Mary Ellen Mark)

Children wave Vietnamese and American flags while waiting for arrival of U.S. President Barack Obama (not pictured) before a welcoming ceremony at the Presidential Palace in Hanoi, Vietnam May 23, 2016. (Photo by Reuters/Kham)