[Early morning fog on Mars]
Image Not Available
Photograph
[Early morning fog on Mars]
July 24, 1976
Gelatin silver print
Image: 15.1 x 11.8 cm (each image)
Overall: 19.2 x 25.3 cm
Museum accession
2011.0100.0003
Inscriptions verso (applied label, typed): NATIONAL AERONATICS AND SPACE ADMINISTRATION/ VIKING NEWS CENTER/ PASADENA, CALIFORNIA/ (213) 354-6000/
PHOTO CAPTION/
Viking 1-70/ P-17487 (34A52/62)/ August 13, 1976/
Two pictures taken a half-hour apart by the Viking 1 Orbiter show the development on/ Mars of early morning fog in low spots, such as crater and channel bottoms (see/ arrows on picture at right). Scene at left was photographed shortly after Martian/ dawn on July 24 from 12,400 kilometers (7700 miles) and, at right, 30 minutes later/ from 9800 kilometers (6100 miles). Slight warming of the sub-zero surface by the/ rising sun evidently has driven off a small amount of water vapor which has re-/condensed in the colder air just above the surface. Brightness measurements of the/ resulting fog patches indicate that a film of water about one micrometer (one-/millionth of a meter) thick has condensed. These fog patches are the first direct/ visible evidence as to where the exchange of water between the Martian surface and/ atmosphere is actually occurring.
PHOTO CAPTION/
Viking 1-70/ P-17487 (34A52/62)/ August 13, 1976/
Two pictures taken a half-hour apart by the Viking 1 Orbiter show the development on/ Mars of early morning fog in low spots, such as crater and channel bottoms (see/ arrows on picture at right). Scene at left was photographed shortly after Martian/ dawn on July 24 from 12,400 kilometers (7700 miles) and, at right, 30 minutes later/ from 9800 kilometers (6100 miles). Slight warming of the sub-zero surface by the/ rising sun evidently has driven off a small amount of water vapor which has re-/condensed in the colder air just above the surface. Brightness measurements of the/ resulting fog patches indicate that a film of water about one micrometer (one-/millionth of a meter) thick has condensed. These fog patches are the first direct/ visible evidence as to where the exchange of water between the Martian surface and/ atmosphere is actually occurring.
