Expedition 44 flight engineer and NASA astronaut Scott Kelly seen inside the Cupola, a special module which provides a 360-degree viewing of the Earth and the International Space Station. Kelly is one of two crew members spending an entire year in space. (Photo by Scott Kelly/NASA)

A man exercises in the early morning on a hilltop overlooking Kabul, Afghanistan March 3, 2016. (Photo by Mohammad Ismail/Reuters)

Subway passengers walk past bronze sculptures representing the Soviet people at the Ploshchad Revolyutsii metro station in Moscow, on November 14, 2012. The station was opened in 1938. (Photo by Kirill Kudryavtsev/AFP Photo)

Naked riders seen participating during the World Naked Bike Ride to demonstrate the vulnerability of cyclists on city streets in London, United Kingdom on June 9, 2018. People chose to ride naked to celebrate cycling and body freedom. (Photo by Brais G. Rouco/SOPA Images/LightRocket via Getty Images)

A boy listens to a prayer before he and other relatives visit the grave of their loved ones, all minors, who were killed a year ago during the government's war on drugs campaign, at the Tala Cemetery in Caloocan, east of Manila on December 28, 2017, as the world commemorates Holy Innocents' Day. Catholics celebrate the biblical passage when King Herodes the great ordered to kill all newborn babies to kill Jesus Christ. (Photo by Noel Celis/AFP Photo)

Kashmiri villagers inspecting a house damaged in a gun battle flee from it after hearing rumors of Indian army soldiers returning back to the site, which turned out to be false, in Kundalan village, some 60 Kilometres south of Srinagar, Indian controlled Kashmir, Tuesday, July 10, 2018. Government forces fired at protesters Tuesday in Indian-controlled Kashmir, killing a teenage boy and wounding at least 120 more who had been trying to reach the site of a gunbattle in which soldiers killed two rebels, police and residents said. (Photo by Dar Yasin/AP Photo)

These heartwarming images capture the pure happiness of young children playing with a buffalo in the sweltering Indonesian heat on July 28, 2018. The children are all sons of the farmers who work on the rice farms in the West Java region of Indonesia. Amateur photographer Tamlikho Tam, 46 from Depok in West Java Indonesia snapped up the joyful moment because it shows what a typical childhood should be like without technology. (Photo by Tamlikho Tam/South West News Service)

An Egyptian boy holds a camel at the Berqash camel market northeast of Cairo, on August 17, 2018. Muslims across the world are preparing for the Eid al-Adha holiday when custom requires the faithful to make a sacrifice. (Photo by Khaled Desouki/AFP Photo)