Mars from Mariner 9: Ascraeus Lacus above the Martian Dust Storm

Caption NASA originale:"Oblique view of the crater complex near Ascraeus Lacus in the Tharsis region of Mars taken by Mariner 9. It is the northernmost of the prominent dark spots observed by Mariner during its approach to the Planet. The spot consists of several intersecting shallow crater-like depressions.
The main crater is approximately 21 Km (13 miles) across, the whole complex about 40 Km (25 miles) across.
The crater probably is in a relatively high area of the Martian surface, which accounts for its being visible above the dust storm.
The faint circular features outside the crater are probably atmospheric disturbances".