Browse image
Resolutions offered for this image:
4928 x 3280 pixels 720 x 480 pixels 4928 x 3280 pixels 640 x 426 pixels
Cloud masks available for this image:

Spacecraft nadir point: 24.5° N, 21.8° E

Photo center point: 19.8° N, 18.6° E

Photo center point by machine learning:

Nadir to Photo Center: Southwest

Spacecraft Altitude: 217 nautical miles (402km)
Click for Google map
Width Height Annotated Cropped Purpose Links
4928 pixels 3280 pixels No No NASA's Earth Observatory web site Download Image
720 pixels 480 pixels Yes No NASA's Earth Observatory web site Download Image
4928 pixels 3280 pixels No No Download Image
640 pixels 426 pixels No No Download Image
Other options available:
Download Packaged File
Download a Google Earth KML for this Image
View photo footprint information
Download a GeoTIFF for this photo
Image Caption: Emi Koussi and Wind Grooves

An astronaut aboard the International Space Station (ISS) took this oblique photograph of one of the large volcanoes found in the central Sahara Desert. Emi Koussi is the dark crater and cone occupying most of the image. The dark lavas erupted from the volcano contrast with the surrounding light-toned sands and bedrock. For scale, the Emi Koussi crater is 12 to 15 kilometers wide (7.5 to 9.5 miles). Canyons, which were eroded by rivers and streams, radiate down the slopes. Click here for an earlier photo of the crater depression.

The Emi Koussi cone rises so high above the surrounding plains (2300 meters or 7,500 feet) that it deflects the dominant winds, which curve around the mountain mass. The lack of vegetation in the desert allows these persistent winds to erode long grooves in soft rocks - geologists call them yardangs. The grooves can be 30 meters deep and up to tens of kilometers long, and they reflect the dominant wind directions.

Emi Koussi is one of a line of volcanoes trending north in the range known as the Tibesti Mountains, which are often photographed by ISS crews. Travel across this countryside is known to be extremely difficult due to the challenging terrain.