A walker has left a handprint on a snow- covered tree trunk on Grosser Feldberg mountain in the Taunus mountain range, Germany, 16 January 2017. (Photo by Frank Rumpenhorst/DPA)

A woman shoots her rifle at a forest shooting range near the village of Visnova, Czech Republic, June 9, 2016. (Photo by David W. Cerny/Reuters)

Kenya Wildlife Service and Save The Elephants staff push an elephant as they undertake the collaring of ten elephants ranging near the Standard Gauge Railway to fit them with advanced satellite radio tracking collars in Tsavo National Park, Kenya March 15, 2016. (Photo by Goran Tomasevic/Reuters)

A demonstration on March 15, 1922 on Palace Roof, 57th Street and 7th Avenue, showing the shellproof steel jacket. Leo Krause wearing the jacket, which weighs 12 pounds. Shots used, 38 and 45 calibre, at close range. (Photo by Bettmann Archive)

Alluvial Fan, China. A vast alluvial fan blossoms across the desolate landscape between the Kunlun and Altun mountain ranges that form the southern border of the Taklimakan Desert in China’s XinJiang Province. Image taken by the ASTER instrument on NASA’s Terra satellite on May 2nd, 2002. (Photo by NASA/GSFC/USGS EROS Data Center)

U.S. soldiers from 145th Field Artillery Battalion deployed from the United States fire Paladin self propelled gun during the Foal Eagle training exercise at firing point 180 at the Rodriguez Live Fire Range on March 15, 2012 in Pocheon, South Korea. (Photo by Chung Sung-Jun/Getty Images)

A marine aims an RPG-7, a portable rocket- propelled grenade launcher, during military exercises conducted by the Russian Pacific Fleet' s naval infantry unit at the Bamburovo firing range on February 2, 2017. The drills are a part of preparations for the Suvorov Attack and Sniper Line army competitions. (Photo by Yuri Smityuk/TASS)