Apollo 9 Command/Service Modules (CSM) nicknamed “Gumdrop” and Lunar Module (LM), nicknamed “Spider” are shown docked together as Command Module pilot David R. Scott stands in the open hatch. Astronaut Russell L. Schweickart, Lunar Module pilot, took this photograph of Scott during his EVA as he stood on the porch outside the Lunar Module. Apollo 9 was an Earth orbital mission designed to test docking procedures between the CSM and LM as well as test fly the Lunar Module in the relative safe confines of Earth orbit. (Photo by NASA)

A Naga sadhu, or naked Hindu holy man, performs a ritual inside his tent during Kumbh Mela, or Pitcher festival, at Trimbakeshwar, India, Friday, August 28, 2015. Hindus believe taking a dip in the waters of a holy river during the festival will cleanse them of their sins. The festival is held four times every 12 years. (Photo by Rajanish Kakade/AP Photo)

A riot police blocks a street during a march near a meeting attended by the Secretary-General of Organization of American State Luis Almagro and leaders from various communities in Managua, Nicaragua, December 1, 2016. (Photo by Oswaldo Rivas/Reuters)

In this photo taken Saturday, January 24, 2015, a child makes a face while having her photo taken with the snow covered slopes of the Nanshan ski resort behind her in Beijing. As Beijing makes a final push in its bid for the 2022 Winter Olympics, Chinese President Xi Jinping says winning the bid will encourage over 300 million Chinese to take up winter sports by 2022, according to state-run Xinhua News agency. (Photo by Ng Han Guan/AP Photo)

A vervet monkey passes in front of a woman on the shores of lake Naivasha, Kenya January 24, 2017. (Photo by Goran Tomasevic/Reuters)

Miss France Iris Mittenaere (R) and Miss Haiti Raquel Pelissier hold hands before Mittenaere is announced winner of the 65th Miss Universe beauty pageant at the Mall of Asia Arena, in Pasay, Metro Manila, Philippines January 30, 2017. (Photo by Erik De Castro/Reuters)

Actress Bai Ling poses for a picture in front of St. Basil's Cathedral at the Red Square in Moscow, Russia, July 1, 2015. (Photo by Ivan Burnyashev/Reuters)

A boy walks with toy guns as people ride an APC during a military show at the Finnish Gulf coast in St.Petersburg, Russia, Saturday, September 5, 2015. (Photo by Dmitry Lovetsky/AP Photo)