The Terrestrial Planets

Mars

Small size (the diameter is one-half as large as Earth's)

Beyond our orbit, surface temperatures -20F to 70F

Evidence of surface evolution

High volcanoes (Olympus Mons: 16 miles high) and a history of volcanic eruptions
Deep canyons (Valles Marineris: 4 miles deep, 120 miles wide, 2500 miles long)
Floods (× 10,000 more water than the Mississippi River)
Craters with "splash" features suggesting water landings
Erosion features

Thin, cool atmosphere (carbon dioxide)

Little or no water vapor or liquid water (ice caps?) now, but probable in the past ...

Meteorites show water damage, traces of biological life!

Two moons (Phobos and Deimos, each 20 kilometers in size, distorted in shape)

Rich orange shades of the large dust pains of Mars.
Great Dust Plains Gigantic canyon surrounded by several large volcanic relics spans the Martian surface.
Canyon and Volcanoes A close-up of the Valles Marineris (the largest canyon known in the solar system), a jagged gash extending roughly a quarter of the way around Mars.
Valles Marineris
A view of one Martian hemisphere, with an arctic cap at the North Pole and large light and dark regions covering the surface.
Daily Global Image A large dark patch on the Martian surface.
Cerberus (dark patch) Close-up of features in the Ius Chasma (a large canyon in the southern Martian hemisphere).
Ius Chasma
Images of our sister planet Mars, with its two moons and tremendous volcanoes. [NASA]

Great Dust Plains	Canyon and Volcanoes	Valles Marineris
Daily Global Image	Cerberus (dark patch)	Ius Chasma
Images of our sister planet Mars, with its two moons and tremendous volcanoes. [NASA]