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  Image: Geographic Location Direction Photo #: ISS027-E-9771 Date: Apr. 2011
Geographic Region: INDIAN OCEAN I(S).
Feature: BASSAS DA INDIA, SUNGLINT, ATOLL

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  Bassas da India in Sunglint, Indian Ocean

The vantage point of astronauts on board the International Space Station provides many dramatic views of the Earth’s surface. Occasionally those views become spectacular. This detailed astronaut photograph of the Bassas da India, an uninhabited atoll in the Indian Ocean (between the Mozambique coast of Africa and the island of Madagascar) has an almost surreal quality due to varying degrees of sunglint. Sunglint is an optical phenomena caused by light reflecting off of a water surface directly back towards the observer.

Variations in the roughness of the water surface—presence or absence of waves due to wind and water currents— will cause differences in the intensity of the sunglint. The presence of other materials, such as oils or surfactants, can also change the properties of the water surface. Here the presence of currents is highlighted as darker patches or streaks (image left, image upper right). In contrast, shallow water in the lagoon (image center) presents a more uniform, mirror-like appearance in sunglint suggesting that there are no subsurface currents present. Wave crests visible around the atoll are likely the result of both surface winds and subsurface currents.

The Bassas da India atoll is part of the French Southern and Antarctic Lands. It is uninhabited due to its complete submergence during high tide – there is no vegetation established on the atoll for the same reason. The atoll is approximately 10 km in diameter, and covers an area (including the lagoon) of approximately 80 square kilometers.
 
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Images: All Available Images Low-Resolution 228k
Mission: ISS027  
Roll - Frame: E - 9771
Geographical Name: INDIAN OCEAN I(S).  
Features: BASSAS DA INDIA, SUNGLINT, ATOLL  
Center Lat x Lon: 21.5S x 39.7E
Film Exposure:   N=Normal exposure, U=Under exposed, O=Over exposed, F=out of Focus
Percentage of Cloud Cover-CLDP: 10
 
Camera: N2
 
Camera Tilt: 48   LO=Low Oblique, HO=High Oblique, NV=Near Vertical
Camera Focal Length: 800  
 
Nadir to Photo Center Direction: NW   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: 2897  
 
Date: 20110402   YYYYMMDD
Time: 103147   GMT HHMMSS
Nadir Lat: 24.2S  
Latitude of suborbital point of spacecraft
Nadir Lon: 42.0E  
Longitude of suborbital point of spacecraft
Sun Azimuth: 325   Clockwise angle in degrees from north to the sun measured at the nadir point
Space Craft Altitude: 192   nautical miles
Sun Elevation: 56   Angle in degrees between the horizon and the sun, measured at the nadir point
Land Views: ATOLL, ISLAND  
Water Views: LAGOON, OCEAN, SUNGLINT, WAVE  
Atmosphere Views:  
Man Made Views:  
City Views:  
Photo is not associated with any sequences


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