Mars

Mars from HST An HST image.

Geology Valles Marineris (the huge canyon) in the center and three massive volcanoes on the left in the Tharsis Bulge (Frak197).

Tharsis Bulge Four giant volcanos including Olympus Mons.

South Pole CO_2 ice on water ice. The CO_2 ice sublimes in the summer and refreezes in winter.

On the Surface A true color (?) Viking image from 1970s.

Phobos 27 km at longest. It has 7.3 hour revolution period and so rises west and sets east. It is a disk as seen from surface. Phobos and Deimos were both discovered in 1877 at perihelion opposition (Zei216).

Deimos 15 km at longest. Star-like from surface (Zei216).