“Weapons Instructor”, 2012. It’s a well known fact that the IDF trains some of the best soldiers in the world, but at the source of every good soldier lies an exceptional instructor – and that’s where Cpl. Daniella Stepanoe steps in. She travels from base to base training everyone from paratroopers to elite special forces units in the use of their weapons. (Photo by Israel Defense Forces)

The competition, which is run by the Royal Observatory Greenwich in association with BBC Sky at Night Magazine, is now in its sixth year and has received over 2,500 entries. Photo: Centre of the Heart Nebula by Ivan Eder (Hungary). Situated 7500 light years away in the “W”-shaped constellation of Cassiopeia, the Heart Nebula is a vast region of glowing gas, energized by a cluster of young stars at its centre. The image depicts the central region, where dust clouds are being eroded and moulded into rugged shapes by the searing cosmic radiation. (Photo by Ivan Eder)

In this Friday, January 7, 2011 photo, people carry baskets of coal scavenged illegally at an open-cast mine in the village of Bokapahari in the eastern Indian state of Jharkhand where a community of coal scavengers live and work. The world's biggest coal users – China, the United States and India – have boosted coal mining in 2017, in an abrupt departure from last year's record global decline for the heavily polluting fuel and a setback to efforts to rein in climate change emissions. (Photo by Kevin Frayer/AP Photo)

An archer in a samurai warrior costume aims at a target in the Asakusa Yabusame horseback archery event at Sumida Park in Tokyo, Saturday, April 18, 2015. (Photo by Shizuo Kambayashi/AP Photo)

This file photo provided on Sunday February 15, 2015 by the Syrian anti-government activist group Aleppo Media Center (AMC), which has been authenticated based on its contents and other AP reporting, shows Syrian rebels firing locally made shells against the Syrian government forces, in Aleppo, Syria. (Photo by AP Photo/Aleppo Media Center)

Police haul a youth to the paddy wagon as an undetermined number of arrest were made in downtown Atlanta, Georgia, February 25, 1971, as police moved in to disperse black youths after windows were broken and rocks and fruit thrown in what officers called “a major disturbance”. (Photo by Charles Kelly/AP Photo)

A poster for the IMAX presentation of “The Hunger Games: Catching Fire” (left), and a teaser poster for “The Hunger Games: Mockingjay, Part I”, both created by the Los Angeles-based design firm IGNITION. Both are nominated for the 2014 Key Art Awards in the category of Theatrical Domestic One-Sheet. The Hollywood Reporter's annual competition for the best in film and TV advertising honors some of the most creative imagery used in movie posters. Here is a selection of some of this year's nominees. (Photo by Key Art Awards 2014)

Three workers demonstrating the different types of gas masks used in mine rescue work. (Photo by Fox Photos/Getty Images). December 1925