Mars, the fourth planet from the Sun, is commonly referred to as the "red planet." But images from the High Resolution Imaging Science Experiment camera (HIRISE for short) onboard the Mars Reconnaissance Orbiter reveal surprising colors. (NASA)
This digital terrain model covers the western rim of Endeavour Crater where the Mars Exploration Rover Opportunity has been investigating since 2011. (NASA)
The central hills in Hale Crater is one such location, with thousands of seasonal flows on steep slopes below bedrock outcrops. The cutout shows a small sample of this image, with relatively dark and reddish lines extending onto sediment fans. (NASA)
Syria Planum is a broad plateau, forming part of the Tharsis region, which is home to the largest volcanos in the Solar System. Some of these, Arsia Mons and Pavonis Mons, are called "shield" volcanos. (NASA/JPL/University of Arizona)
This observation was taken as part of the Mars Science Laboratory (MSL) "color image campaign" at Eberswalde Crater. MSL, also known as "Curiosity," is set to launch in November 2011.
Another reason for this observation was to complement CRISM color images at HiRISE resolution. CRISM has detected phyllosilicates (clays) in the region. Clays on Earth are often formed in the presence of water and occur in river deltas and lake beds. On Mars, could this be evidence for past water activity? (NASA/JPL/University of Arizona)
Dark dunes and sand streaks are the highlights of this observation, all confined inside this valley.
In such a complex topographic environment, winds could be funneled above the threshold for sand movement. New images of the area can tell us more about the extent of aeolian activity here. (NASA/JPL/University of Arizona)
Crystalline gray hematite (Fe2O3) was first detected on Mars using the Thermal Emission Spectrometer (TES). The landing site for the Mars Exploration Rover (MER) Opportunity was chosen at one of these hematite sites in Meridiani Planum.
After landing and driving around on the surface, scientists discovered that the hematite occurred in millimeter-size rounded particles that were concentrated along the upper surfaces of the soils.
In this HiRISE image taken within Capri Chasma, TES also detected the same crystalline gray hematite like that found at Meridiani Planum. The enhanced-color image shows a red surface, consistent with a material that contains the element iron. The plains here are similar to those seen at Meridiani Planum and suggest that hematite-rich particles are concentrating on the upper soils where they can be detected from orbit by TES. (NASA/JPL/University of Arizona )
Images from NASA's rovers have given us a clear view of what it would be like to stand on Mars -- dusty, red and dry. Here, the Spirit rover records a view across Gustev crater. But the view from outer space presents a very different view of the nearby planet. (NASA/JPL)
No, Mars didn't get hit by an oil spill too. The planet's south polar cap has various surfaces. During the spring, shown here, Mars' surface is covered by carbon dioxide frost. (Image: NASA/JPL/University of Arizona)
The approximately 800-meter Victoria Crater lies near the equator of Mars and is home to sand dunes resting on its floor. The rim's shape is caused by erosion and the downhill movement of the crater wall. (Image: NASA/JPL/University of Arizona)
Surf's up? It may look like a great time to grab your surf board on the West Coast, but that's actually dark sand covering bright bedrock in the Terra Meridiani region of Mars. It's likely the basaltic sand formed from the breakup of volcanic rock. (Image: NASA/JPL/University of Arizona)
These north-polar layered deposits are found in Chasma Boreale, a large canyon on Mars. It's likely that water ice is responsible for the color pattern. Images like these are useful in understanding the planet's recent climate variations. (Image: NASA/JPL/University of Arizona)
Gullies of all elevation and sizes have formed in a crater in Terra Sirenum. (Image: NASA/JPL/University of Arizona)
Gullies and ridges cover much of Mars. Dust and water frost, like the bright areas, make up these formations. (Image: NASA/JPL/University of Arizona)
Was someone off-roading on Mars? These north polar layered deposits probably contain ice and dust layers. The darker layers likely hold more dust than the brighter layers. (Image: NASA/JPL/University of Arizona)
A portion of the central sedimentary deposits in Pasteur Crater is now eroding. Wind-blown dust may have caused the appearance of the deposits. (Image: NASA/JPL/University of Arizona)
This image shows dark sand dunes in Chasma Boreale, a giant trough that cuts into the north polar ice cap for 570 kilometers (350 miles) forming a broad valley bordered by stacked layers of ice. These dark dunes are <i>barchan </i>dunes also commonly found on Earth -- crescent-shaped with a steep slip face bordered by horns oriented downwind. Barchan dunes form by uni-directional winds and thus are good indicators of the dominant wind direction. (NASA/JPL/University of Arizona)
Tis' the Season. This is what a crater in Mars' southern hemisphere looks like during winter. The bright colors are either carbon dioxide or water frost. (Image: NASA/JPL/University of Arizona)
Is that an ice-skating rink? Nope, just a dune field in Bunge Crater on Mars. (Image: NASA/JPL/University of Arizona)
The dune field in the northeast portion of Russell Crater is roughly 30 kilometers long, and appears to have formed from windblown material trapped by the local topography. This image was taken during the southern hemisphere's deep winter, where temperatures are low enough to allow the carbon dioxide frost to be stable. The frost is apparent primarily on the slopes that do not experience full sunlight. (NASA/JPL/University of Arizona)
In the winter, these dunes in an unnamed crater east of Proctor Crater are covered with seasonal carbon dioxide frost (dry ice). In the spring, the frost gradually evaporates but lingers in protected regions. In this color image bright ice deposits in sheltered areas highlight the ripples on the dunes. (NASA/JPL/University of Arizona)
NASA's Mars Reconnaissance Orbiter took this picture, which is quite the optical illusion: What appears to be trees rising from the Martian surface are actually dark streaks of collapsed material running down sand dunes due to carbon dioxide frost evaporation. (NASA/JPL/University of Arizona. )