Archive for November 19th, 2009

NASA’s Terra & Aqua satellites take pictures of recent snowfalls in North America and China. With higher resolution goodness as usual, so click them!

Acquired November 18, 2009

In mid-November 2009, a band of snow stretched across Ontario between James Bay and Lake Superior. North of Lake Superior, Lake Nipigon interrupted the broad band of snowy white. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this true-color image on November 18, 2009. Snow cover appears thickest near James Bay, gradually tapering off toward the southwest.

Average annual snowfall in Ontario ranges from 200 to 400 centimeters (80 to 160 inches), with the greatest accumulations usually near lake Superior.

Acquired November 17, 2009

Not long after the snow from an October storm melted, the Denver area experienced another significant autumn snowstorm, on November 14–15, 2009. According to the National Weather Service, accumulation amounts in northeast and north central Colorado ranged from 3 to 15 inches (8 to 38 centimeters). Hardly confined to the Denver area, snowfall occurred across the Rocky Mountains, well into the western part of the state. Snowfall also stretched into Wyoming, Nebraska, and Kansas.

The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this true-color image on November 17, 2009. Snow blankets almost the entire northeastern quadrant of Colorado, interrupted by the urban gray of the Denver metropolitan area. The blanket of snow extends into the plains of southern Wyoming, southwestern Nebraska, and western Kansas.

Even heavier amounts of precipitation fell west of Denver, but the snow appears far less uniform in rugged foothills and mountains. West of the city, snowcaps create dendritic patterns over the Rocky Mountains, some of this snow left by earlier storms.

Acquired November 17, 2009

On the ground, snow is an equalizer. It covers everything with a uniform blanket of white, making both the dingiest trash heap and the loveliest garden a pristine field of white. But from space, snow highlights features that would ordinarily blend into the landscape. This photo-like image, captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite, provides an example.

The image is from November 17, 2009, days after a large snow storm swept over China, covering much of the country in white. This image shows part of the North China Plain near the city of Shijiazhuang. On the plain, the snow is white where it fell on fields or natural landscapes. Artificial surfaces in cities, towns, and roads are gray. While the larger cities and towns would be visible on a day without snow or clouds, many of the smaller towns and roads would be difficult to distinguish from the surrounding landscape. In the snow, however, small towns and the roads that connect them stand out clearly.

The storm that brought the snow came unusually early in the winter. The snowfall, the heaviest in decades, killed at least 32 people, destroyed 300,000 hectares of crops, and caused more than 15,000 buildings to collapse, reported Xinhua, the Chinese news agency. The storm closed roads and curtailed train and air travel. Airports in many large cities, including Shijiazhuang, closed.

Image of Tehran, Iran, the first image taken in 1985 and the next in 2009. Both by the Landsat 5 satellite. To learn more about the landsat program go here.

Acquired August 2, 1985

Acquired July 19, 2009

Tehran, Iran’s capital, ranks among the world’s fast-growing cities. In the early 1940s, Tehran’s population was about 700,000. By 1966, it had risen to 3 million, and by 1986—during the Iran-Iraq war—migrants brought the population to 6 million. Today, the metropolitan area has more than 10 million residents, more than the sum of the country’s next five major metropolitan areas combined. This explosive growth has environmental and public health consequences, including air and water pollution and the loss of arable land.

The Thematic Mapper sensor on NASA’s Landsat 5 satellite acquired these false-color images of Tehran on August 2, 1985 (top), and July 19, 2009 (bottom). In both images, vegetation appears bright green, urban areas range in color from gray to black, and barren areas appear brown. Whereas non-urbanized areas fringe the earlier image, urbanization fills almost the entire frame of the later image. Major roadways crisscrossing the city in 1985 remain visible in 2009, but many additional roadways have been added, particularly in the north.

Tehran sits on a gradually sloping plain between the Alborz Mountains in the north and the Great Salt Desert in the south. The city has been populated for thousands of years. It began as a village outside the ancient city of Ray, sitting at the intersection between the east-west Silk Road, and the north-south route between the Caspian Sea and Persian Gulf.

Throughout the city’s long history, generations of city planners have attempted to manage Tehran’s growth. Authorities constructed a bazaar and city walls in the sixteenth century, and an expanded set of walls in the nineteenth century. By the 1930s, a new generation of city planners were building boulevards atop the old walls’ ruins.

Video flight day 3 highlights, most notably RPM, docking, the meeting of the two crews.

Image from the Mini-RF instrument aboard LRO, details below the image.

Mini-RF S-band zoom synthetic aperture radar (SAR) image strip through central Mare Serenitatis on the near side of the Moon (approximate longitude of strip ~ 18° E; center latitude ~ 20° N). The radar strip runs through the crater Bessel (inset; 15 km (9 mile) diameter; center at 21.8° N, 17.9° E) and covers the highlands of the Haemus Mts. (rim of Serenitatis basin) in its southern (bottom) third. The full-resolution SAR data are 30 m (90 feet). The streaks of bright and dark material in the walls of Bessel probably reflect the blockiness of landslides within the crater, brighter streaks having more blocks of the 10-cm (4-inch) scale. The radar strip covers a major geological boundary in Mare Serenitatis; the darker, lower maria has higher titanium content than central Serenitatis. We see this geological boundary in the Mini-RF radar image, caused by higher absorption of RF energy by the high content of the iron-titanium oxide mineral ilmenite. Thus, Mini-RF SAR images can be used to map the titanium content of the lunar maria. The background image is part of the Clementine global mosaic.

In just 19 days on December 9th, the Wide-field Infrared Survey Explorer will launch from Vandenberg Air Force Base in California. Below is video that gives you an idea of what WISE will be accomplishing for the scientific community.

NASA astronauts Nicole Stott & Jeff Williams of Expedition 21, show off some of the food they’ll be eating over Thanksgiving and send all on earth season greetings.