In this Thursday, March 17, 2016 photo, 33-year-old Palestinian clown doctor Alaa Miqdad, left, entertains 3-year-old patient Yaqin Shawaf, who suffers from dialysis, in the department of kidney diseases at Al-Rantisi children's hospital in Gaza City. (Photo by Adel Hana/AP Photo)

In this June 8, 2015 photo, Omkarnath, who goes by the name “Medicine Baba”, pays his reverence at a neighborhood temple as he begins his day in New Delhi, India. The chatty, 79-year-old retired blood-bank technician has been collecting unused prescription drugs from the affluent for the past eight years, and distributing whatever hasn't expired to patients who need medicines they cannot afford. (Photo by Saurabh Das/AP Photo)

Dancers from the “Legend Lin Dance Theatre” perform the artistic director and choreographer Li-chen Lin's classic works “Hymne aux Fleurs qui Passent, Anthem to the Fading Flowers” during a rehearsal at the National Theater Concert Hall in Taipei, Taiwan, Tuesday, August 18, 2015. “Hymne aux Fleurs Qui Passent” pays tribute to the cycle of the year and the complementary principles of Yin and Yang whose eternal struggle provides the driving force behind the changing of the seasons. (Photo by Chiang Ying-ying/AP Photo)

Throughout the course of the long war in Afghanistan, Coalition troops have relied on thousands of military working dogs to help keep them safe, and make their jobs easier. The dogs are trained to detect explosives, to find illegal drugs, to search for missing comrades, or target enemy combatants. Not only are they active on the front lines, but behind the lines they serve as therapy dogs, service dogs, and loyal companions. They also share the same risks as the ground troops, suffering injuries and sometimes death on the battlefields. Gathered here are images of these dogs and their handlers in Afghanistan and back home, from over the past several years, part of the ongoing series here on Afghanistan.

“NASA's Mars rover Opportunity just celebrated its ninth anniversary on Mars – a mission that was originally meant to last just 90 days...” – The Atlantic. Photo: NASA's rover Opportunity visits Victoria Crater, viewed from orbit by the High Resolution Imaging Science Experiment on NASA's Mars Reconnaissance Orbiter in october of 2006. Opportunity is a small dot on the crater's lip, at top right. Opportunity first reached the crater's rim on September 27, 2006. (Photo by NASA/JPL-Caltech/University of Arizona via The Atlantic)

A 210-kilogram-weight Epinephelussp was showed at China Fisheries & Seafood Expo in Fuzhou, Fujian, China on 24th October, 2014. (Photo by Top Photo/Sipa Press USA)

In this April 7, 2015 photo, a tourist peers through the door of a jail cell inside the now empty Garcia Moreno prison during a guided tour for the public in Quito, Ecuador. According to tour guides, this cell was nicknamed “Los Polillas”, or “The Moths”. Here, in a room designed to hold two prisoners, about 15 inmates with drug addictions were locked in overnight by the prison gangs that controlled daily life. The locked-in prisoners were also known to prostitute themselves to get access to drugs. (Photo by Dolores Ochoa/AP Photo)

Local residents evacuate onto a street minutes after an earthquake in central Kathmandu, Nepal, May 12, 2015. A 7.3 magnitude earthquake killed at least 37 people and spread panic in Nepal on Tuesday, bringing down buildings already weakened by a devastating tremor less than three weeks ago and unleashing landslides in Himalayan valleys near Mount Everest. The earthquake was centered 76 km (47 miles) east of the capital in a hilly area close to the border with Tibet, according to coordinates provided by the U.S. Geological Survey. (Photo by Athit Perawongmetha/Reuters)