Letter M - On August 14, 2015, the Operational Land Imager (OLI) on Landsat 8 captured this image of glaciers in the Tian Shan mountains in northeastern Kyrgyzstan. The trail of brown sediment in the middle of the uppermost glacier is a medial moraine, a term glaciologists use to describe sediment that accumulates in the middle of merging glaciers.[Photo/IC]