Bend in the Nile, By Day and Night
the Nile delta in the north and the Sudanese border in the south,
the Nile River cuts a deep U-shaped bend into the desert near Luxor.
A mosaic of three digital photographs taken from the International
Space Station shows the regional pattern and context of Nile agriculture
in the desert. Viewed during the day, the dark river channel is
bordered by green fields of the intensely farmed floodplain, with
a few grayer areas showing the locations of urban areas. The sharp
margins of the agriculture generally mark a distinct break between
the valley floor and local dry wadis that lead down from the desert
plateau. The patchy, green areas at places along the edge of the
floodplain, which are very prominent south of Naj' Hammadi, indicate
where irrigation has expanded up onto the dry slopes.
The Nile has
entrenched itself by erosion into the desert plateau by 305 to 457
meters (1000 to 1500 feet), producing a maze of steep-sided valleys,
many with cliffs. The older upper surface of the plateau is slightly
darker than the younger valley surfaces eroded into it due to the
buildup of darker "desert varnish" minerals on rock surfaces. The
older surfaces show another interesting geological feature known
as eolian streaks. These are two-dimensional features generated
by dominant winds from the northwest. These are long, lighter colored
features of moving sand or areas where sand has been swept away.
ancient Thebes, is the location of the great necropolis known as
the Valley of the Kings, which is indicated in the top image by
an arrow. By using the full detail in one of the space station photographs
-- circled in the detailed view -- the light colors show archaeological
excavation. The valley is a narrow, easily defended ravine where
the plateau extends closest to the Nile and to the city of Luxor.
Possibly more important was the valley's symbolic location on the
west side of the Nile in the direction of the setting sun, which
was associated with the afterlife. The sun passed over the pharaoh's
mortuary temple, built for the Egyptians' cult on the floodplain
near Thebes, and then over the pharaoh's tomb in the valley, a symbolically
Once the sun
sets over the Nile, modern lighting outlines a unique set of features.
During his tenure on the space station, Astronaut Don Petit used
door tracker" to take the above nighttime photograph of the
bend in the Nile. Cities can be identified at night by their bright
lighting. By comparing the daytime
and nighttime views of Nile, one can see that lights follow geological
patterns as well. A faint strip of shoreline lights outlines the
dark line of the river. Cities such as Luxor and Qena are bright
and striking. Well-lit roads, such as the one from Luxor to its
airport, which appears as a bright dot, can be distinguished. A
very unique feature of this night photograph is that the pattern
of settlements on the slopes rising from the Nile valley produces
the final outside strip of lighting.
were taken from the International Space Station on 14 February 2003
using a digital camera and 180 mm lens. Astronaut photograph ISS006-E-44645
was taken on 11 April 2003 using a "barn door tracker" and an 85
mm lens. Images, mosaics and information were provided by the Earth
Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed
at the NASA-JSC Gateway to Astronaut
Photography of Earth.