ISS003-E-6632
|
Tibetan Braid: On October 13, 2000, the Expedition 3 crew of
the International Space Station, high over Tibet, took this
interesting photo of the Brahmaputra River. This mighty Asian river
carves a narrow west-east valley between the Tibetan Plateau to the
north and the Himalaya Mountains to the south, as it rushes eastward
for more than 1500 km in southwestern China. This 15-km stretch is
situated about 35 km south of the ancient Tibetan capital of Lhasa
where the river flow becomes intricately braided as it works and
reworks its way through extensive deposits of erosional material.
This pattern is indicative of a combination heavy sediment discharge
from tributaries and reduction of the river’s flow from either a
change in gradient or perhaps even climate conditions over the
watershed. The light color of the deposits and the milky color of
the water is attributed to presence of glacial “flour,” the
fine material created by erosion from glaciers. Besides erosion by
water and ice, this scene also depicts features created by wind.
Note the delicate field of dunes on the alluvial fan toward the right
edge of the image. The riverbed here is at an elevation of over
3,500 m, and with the long west-east extent of this barren valley,
strong, persistent westerly winds also move and shape these deposits.
Photos such as this one bring immediate visual understanding and
appreciation of natural processes in some of the most remote
locations on Earth.
|
ISS003-E-6430
|
ISS Astronauts View the Moon: Inspired by the nearly-full
moon, space station astronauts used an 800 mm lens to study the
craters and mare. This view, taken October 5, 2001, is centered on
Crater Copernicus, surrounded by the Mare Serenitatis and Mare
Tranquillitatis (Sea of Serenity and Sea of Tranquility), Mare
Imbrium (Sea of Rains), Oceanus Procellarum (Ocean of Storms) and
Mare Nubium (Sea of Clouds). The bright crater and ejecta trails of
Tycho dominate this near-side view. For scale, the crater of Tycho is
85 km in diameter.
|
