A snowflake from Kiruna Sweden. Large, well-formed crystals like this one, which is between 2 and 5 mm, usually form when the temperature is around -15 degrees Celsius. A special photo-microscope and colored lights were used to capture the image. Kenneth Libbrecht/Lenart Nilsson Award hide caption

itoggle caption Kenneth Libbrecht/Lenart Nilsson Award

In October, soldiers with the 101st Airborne Division on patrol in eastern Afghanistan's Kunar province climb the hills and footpaths near the Pakistan border. This volatile border has been a source of constant friction as insurgents pass freely through the mountainous region. David Gilkey/NPR hide caption

itoggle caption David Gilkey/NPR