* Sahra Desert *
Terkezi Oasis
Dominating the top third of Africa is the Sahra Desert, Earth's largest band of dry land. Stretching across the Sahara are vast plains of sand and gravel, seas of sand dunes and barren rocky mountains.
Only 10,000 years ago grasses covered the region and mammals such as lions and elephants roamed the land. Now only two percent of the Sahara hosts oases, patches of land usually centered on natural water springs where crops
will grow and where nearly two million people live. This image, taken by Landsat 7, is of a colorful and rocky expanse spanning about 50 kilometers near the Terkezi Oasis in Chad.
Image credit: NASA
* A Atlantis *
Atlantis Lifts Off!
Photographers crowd around the countdown clock to capture the successful launch of Space Shuttle Atlantis from Launch Pad 39A. The shuttle is delivering a new segment to the starboard side of the International Space Station's backbone, known as the truss. Three spacewalks are planned to install the S3/S4 truss segment, deploy a set of solar arrays and prepare them for operation. STS-117 is the 118th space shuttle flight, the 21st flight to the station, the 28th flight for Atlantis and the first of four flights planned for 2007. Image credit: NASA/Jim Grossmann
Photographers crowd around the countdown clock to capture the successful launch of Space Shuttle Atlantis from Launch Pad 39A. The shuttle is delivering a new segment to the starboard side of the International Space Station's backbone, known as the truss. Three spacewalks are planned to install the S3/S4 truss segment, deploy a set of solar arrays and prepare them for operation. STS-117 is the 118th space shuttle flight, the 21st flight to the station, the 28th flight for Atlantis and the first of four flights planned for 2007. Image credit: NASA/Jim Grossmann