In this image from NASA's Mars Reconnaissance Orbiter spacecraft, an ancient sinuous meandering river system is surrounded by features called 'yardangs.' The yardangs are the ridge-like landforms that align approximately north-south.
Small Channels and a Rocky Patch in the Cydonia Region
The southern section of Cydonia Region is dominated by both a series of craters and the remnants of channels that may be from a past fluvial system as seen by NASA's Mars Reconnaissance Orbiter spacecraft.
This image from NASA's Mars Reconnaissance Orbiter spacecraft shows numerous branching ridges with various degrees of sinuosity. These branching forms resemble tributaries funneling and draining into larger channel trunks towards the upper portion.
Kasei Valles is a valley system was likely carved by some combination of flowing water and lava. In some areas, erosion formed cliffs along the flow path resulting in water or lava falls as seen by NASA's Mars Reconnaissance Orbiter spacecraft.
The hills in the relatively-smooth region surrounding this image are flat topped erosional remnants or mesas with irregular or even polyhedral margins in this image from NASA's Mars Reconnaissance Orbiter spacecraft.
Western Edge of Mars' Marth Crater, a Movie Location
In the best-selling novel 'The Martian' and the movie based on it, stranded astronaut Mark Watney's adventures take him to the rim of Mawrth Crater. This image from NASA's Mars Reconnaissance Orbiter shows the nature of this terrain.
This image from NASA's Mars Reconnaissance Orbiter shows a location on Mars associated with the best-selling novel and Hollywood movie, 'The Martian.' It is the science-fiction tale's planned landing site for the Ares 4 mission.
This image from NASA's Mars Reconnaissance Orbiter spacecraft shows modified barchan dunes with shapes that resemble 'raptor claws.' The unusual morphology of these dunes suggests a limited supply of windblown sand.
This image from NASA's Mars Reconnaissance Orbiter spacecraft provides information about erosion and movement of surface material, about wind and weather patterns, even about the soil grains and grain sizes.
Animation of Site of Seasonal Flows in Hale Crater, Mars
This frame from an animation simulates a fly-around look at one of the places on Mars where dark streaks advance down slopes during warm seasons, possibly involving liquid water. This image is from NASA's Mars Reconnaissance Orbiter.
The dark, narrow streaks flowing downhill on Mars at sites such as this portion of Horowitz Crater are inferred to be formed by seasonal flow of water on modern-day Mars in this image from NASA's Mars Reconnaissance Orbiter.
Dark narrow streaks, called 'recurring slope lineae,' emanate from the walls of Garni Crater on Mars, in this view constructed from observations by the HiRISE camera on NASA's Mars Reconnaissance Orbiter.
These strange features in Syria Planum have the same general form as transverse aeolian ridges (TARs) elsewhere on Mars; windblown deposits that are common in the Martian tropics, as seen by NASA's Mars Reconnaissance Orbiter spacecraft.
Possible Sulfates in the Northeast Syrtis Major Region
A variety of diverse morphological features are present in this image located in the southeastern area of the Nili Fossae region and just northeast of Syrtis Major as seen by NASA's Mars Reconnaissance Orbiter spacecraft.
This is a close-up from NASA's Mars Reconnaissance Orbiter spacecraft of the western Medusa Fossae formation where we can see dust-covered rocky, bedrock surfaces (beige) and a bluish-tinted sand sheet that transitions into several dunes.
Rocks Here Sequester Some of Mars' Early Atmosphere
This view combines information from two instruments on NASA's Mars Reconnaissance Orbiter to map color-coded composition over the shape of the ground in a small portion of the Nili Fossae plains region of Mars' northern hemisphere.