Steppe-desert border, satellite image. North is at top. Arid areas of desert rock are brown, while grassy steppe areas are green. A small area of desert sands (yellow) is seen at far centre right. Water in lakes (top centre) is dark blue. This area, called the Edrengiyn Nuruu, forms a transition zone between the Mongolian steppes to the north and the arid deserts of northern China to the south. The area shown in this image is around 170 kilometres wide. The image data includes infrared wavelengths, and was obtained on 13 August 1999, by the Landsat 7 satellite.