Friday, December 14, 2012

"Alaska At Night" An Outgrowth Of NASA's "Earth At Night"

On December 14th, 2012, Dermot Cole highlights NASA's "Earth At Night" project in the Fairbanks Daily News-Miner, and includes a screenshot of an image taken over Alaska. The screenshot does not include southeast Alaska.

So I went hunting for the origin of this imagery, and found it on the NASA Earth Observatory website, selecting the Night Lights 2012 - Flat map category, then downloading the large image (9 MB, JPEG, 13500x13500). A screenshot of the Alaska portion is displayed below:

Standing out are four general areas of illumination; from south to north, the Kenai-Soldotna area, the Anchorage Bowl with Mat-Su immediately proximate, Fairbanks metro, and the North Slope oil fields. The band of light on the North Slope reflects the need for having almost all portions of the complex illuminated at night. However, the photo can be dramatically magnified, and here are two screenshots of the magnifications, the first showing South Central Alaska, and the second showing Fairbanks Metro:

Progressing from the lower left, you can see the Kenai-Soldotna-Sterling area, with the curvature of Homer to the south. To the northeast lies the Anchorage Bowl immediately followed by the Palmer-Wasilla Corridor of the Mat-Su Valley. Note how the Glenn Hwy appears as a bright ribbon of light between Anchorage and Mat-Su. Immediately to the east of the Anchorage Bowl, you can see Girdwood and Whittier; much further to the east, the port of Valdez, with Cordova to the southeast and Glennallen to the north-northeast. Heading north from Mat-Su, you can see the communities of Big Lake-Houston, Willow, and Talkeetna; almost due south of Anchorage, you can see Seward, and the Spring Creek Prison immediately east of Seward is also illuminated.

Anchorage and Mat-Su are included in the extreme lower left for perspective. At the center lies the Fairbanks Metro Area, curving towards North Pole to the southeast. Continuing southeast is Delta Junction, Paxson, and Glennallen; northeast is Tok. Southwest of Fairbanks is Nenana, Clear, and Healy.

According to NASA, the composite photo of the whole earth was assembled from data acquired by the Suomi NPP satellite. The data was acquired over nine days in April 2012 and 13 days in October 2012. It took 312 orbits to get a clear shot of every parcel of Earth's land surface and islands. This new data was then mapped over existing Blue Marble imagery of Earth to provide a realistic view of the plane. Visible Earth was also involved in the project.

NASA and Visible Earth do not object to their images being republished so long as both are given credit and links posted back to their pages. This criteria has been met in the post.

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