Mars - Mariner 9
Mars' north polar cap
Mariner 9 image of the north polar cap of Mars.
The image was taken on 12 October 1972, about
one-half Martian month after summer solstice,
at which time the cap had reached its minimal extent.
The cap is about 1000 km across. The interior dark
markings are frost-free sun-facing slopes.
A smooth layered sedimentary deposit underlies
the cap. The image is centered at 89 N, 200 W.
(Mariner 9, MTVS 4297-47)
