Earth from Space - Image Information

LOCATION Photo #: ISS036-E-28913 Date: Aug. 2013
Geographic Region: PACIFIC OCEAN

Sunset over the Aleutian Islands, with Noctilucent Clouds

Astronauts took this panoramic view looking north from the Aleutian Islands when the International Space Station (ISS) was flying east at "the top of the orbit," the northernmost latitude reached by the ISS (51.6 degrees north). If the sun had been higher, the string of Aleutian Islands would have been visible in the foreground. Here the islands are on the dark side of the day-night line. From their vantage point at 222 km altitude on this day, astronauts were able to see as far north as the Arctic Ocean and the midnight sun. This image was taken just 20 minutes after local midnight in early August 2013. The midnight sun makes the red, diamond-shaped teardrop reflection (lower center of the image)--perhaps a reflection within the camera lens, or from the window frame, or some item inside the ISS.

Long blue-white stringers can be seen in the atmosphere above the midnight sun. These are known as noctilucent clouds (night-shining clouds). Some astronauts say these wispy, rippling, iridescent clouds are the most beautiful phenomena they see from orbit. Noctilucents are thin so that they are best seen after sunset when the viewer is on the night side of the day-night line, but while these high clouds are still lit by the sun. Crews are trained in this somewhat complicated geometry--of clouds being lit from beneath, with the space craft in sunlight though the ground directly beneath is in darkness.

Noctilucent clouds are also known as Polar Mesospheric Clouds (PMCs) as they appear in the summer hemisphere over polar latitudes. Some data suggest that they are becoming brighter, and appearing at lower latitudes, perhaps as an effect of global warming. Polar Mesospheric Clouds are interesting to scientists because they form much higher in the atmosphere (75-90 km) compared with altitudes of normal rainclouds that form in the lowest, densest "weather-layer" below ~15 km. The weather layer, or troposphere, is most distinct in this image as a thin orange line along the left horizon.

Images: All Available Images Low-Resolution 88k
Mission: ISS036  
Roll - Frame: E - 28913
Geographical Name: PACIFIC OCEAN  
Center Lat x Lon: N x E
Film Exposure:   N=Normal exposure, U=Under exposed, O=Over exposed, F=out of Focus
Percentage of Cloud Cover-CLDP: 0
Camera:: N5
Camera Tilt: HO   LO=Low Oblique, HO=High Oblique, NV=Near Vertical
Camera Focal Length: 50  
Nadir to Photo Center Direction:   The direction from the nadir to the center point, N=North, S=South, E=East, W=West
Stereo?:   Y=Yes there is an adjacent picture of the same area, N=No there isn't
Orbit Number:  
Date: 20130804   YYYYMMDD
Time: 112016   GMT HHMMSS
Nadir Lat: 51.6N  
Latitude of suborbital point of spacecraft
Nadir Lon: 170.7W  
Longitude of suborbital point of spacecraft
Sun Azimuth: 358   Clockwise angle in degrees from north to the sun measured at the nadir point
Space Craft Altitude: 222   nautical miles
Sun Elevation: -21   Angle in degrees between the horizon and the sun, measured at the nadir point
Land Views:  
Water Views:  
Atmosphere Views:  
Man Made Views:  
City Views:  

Photo is not associated with any sequences

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