United kingdom Daily news: Dust to dust: Space station captures ultra-rare 75-mile white plume of powder blowing over dune fields of New Mexico

Selasa, 01 Mei 2012

Dust to dust: Space station captures ultra-rare 75-mile white plume of powder blowing over dune fields of New Mexico

Dust to dust: Space station captures ultra-rare 75-mile white plume of powder blowing over dune fields of New Mexico

By Rob Waugh

PUBLISHED: 08:20 EST, 1 May 2012 | UPDATED: 12:18 EST, 1 May 2012

The plume of icy white dust stretches for more than 75 miles - and the sheer force of the wind 'lifts' the dust more than four thousand feet so they float over the Sacramento mountains.

The photograph was taken from the International Space Station, 245 miles up - and shows one of the only places on Earth where white dust 'takes flight' on the wind.

Driven by southwesterly winter winds, dust from the White Sands dune field in New Mexico rises thousands of feet from the valley floor and drifts over the snowy peaks of the Sacramento Mountains

The plumes of dust were also captured by the MODIS instrument on board Nasa's Terra satellite

The white dunesâ€™ brilliance - they are made of gypsum - especially contrasted against the nearby dark mountain slopes, makes them easily identifiable to orbiting astronauts. The white speck of the dunes was even visible to astronaut crews looking back at Earth on the way to the Moon.

Driven by southwesterly winter winds, dust from the White Sands dune field in New Mexico rises thousands of feet from the valley floor and drifts over the snowy peaks of the Sacramento Mountains.

White Sands National Monument lies in the 31 mile wide Tularosa valley, between the dark rocks and forested slopes of the Sacramento Mountains and the San Andres Mountains.

The lower and warmer ridge line of the San Andres was without snow on the day this photograph was taken. The striking black lava flows of the Carrizozo lava field also occupy the valley floor (image top).

The darker tones of agriculture in the Rio Grande floodplain can be seen along the left margin of the image.

The winds channel the dust through a low point in the mountains, about 2400ft lower than the ridge crests to north and south (image right). The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASAâ€™s Aqua satellite also captured a wider, regional view of the plumes on the same day.

In most parts of the world, blowing dust is some shade of light brown or red. In this image, two different colors can be seen in the dust plume: redder dust from the hillsides north of White Sands and white dust from the dune field itself.

The sand dunes of this national monument are white because they are composed of gypsum, a relatively rare dune-forming mineral. The gypsum is deposited during the evaporation of mineral-rich waters in an ephemeral lake in the western part of the Monument. Erosion of the deposits, together with wind transport, provides the gra nular material for the dunes.