Terrain Near the MSL Landing Site

This image is of a region slightly to the southwest of where the MSL rover, called Curiosity, will land in August 2012.

It shows three distinct terrains: (a) older plains, (b) an overlying unit with a distinct margin, and (c) recent sand dunes. The dunes indicate that the strongest winds tend to blow from the southwest toward the northeast and, like many dune fields on Mars, are probably moving slowly.

The second unit has a margin that, at low resolution, is similar to a lava flow. It also has a hard surface that retains impact craters better than the older plains beneath it.

At full HiRISE resolution it is evident that this deposit is not lava. It has thin layers and a dense network of fractures across its surface. The tops of some lava flows and lava lakes are also fractured. However, HiRISE has confirmed that the size and other characteristics of lava fractures are quite different from the ones visible here. Hence, this is some kind of sedimentary deposit, possibly consisting of largely of hardened mud.

It is likely that Curiosity will have an opportunity to investigate terrain like this soon after landing as it drives to the layered mound to the south.

Photo credit: NASA/JPL/University of Arizona

Active Dune Gullies in Kaiser Crater

Gullies remain an interesting feature to study on Mars, especially because we are still learning about their formation and what processes still act on them.

In this observation, we see large gullies on a huge, barchan dune. We've observed these gullies before, seeing that they appear to be active at different times. When we say "active," we mean that we can see changes in their appearance between different HiRISE images of the same area.

The major objective of this and similar images is to better understand the mechanism for these changes. A specific hypothesis the HiRISE team is investigating is that the changes we see are associated with frost deposits. The frost may be thick and heavy enough to cause parts of the sand dune to collapse, especially if it is "lubricated" by a layer of gas at the base of the frost layer. The gas would form at the bottom of the frost if sunlight passes through the frost and heats the underlying dark sand, working like a greenhouse.

Photo credit: NASA/JPL/University of Arizona

Disappearing Boulder Tracks

This image was taken in February 2012, in order to compare against image ESP_017985_1985, which was acquired in May 2010. These two images are separated by approximately one Mars year.

The original image showed a prominent series of dark markings that are the tracks left by boulders as they rolled and bounced down the slope. As they do this, they set off miniature dust avalanches. The bright, fine dust slides away, leaving a darker, larger grained dust underneath.

This follow-up image shows that the smaller dark tracks are gone, and the larger ones have faded considerably. This is most likely due to the fine bright dust that is transported in the atmosphere falling down and re-covering the dark markings.

Photo credit: NASA/JPL/University of Arizona

Note: This crater is located in southeastern "peninsula" of far northwestern Terra Cimmeria that borders northeastern Isidis Planitia.

Late Springtime Defrosting of Northern Dunes

This observation shows dunes in the Martian north polar sand sea (commonly referred to as the "north polar erg") in the process of defrosting.

Every winter, dunes and other surfaces at these northern latitudes are coated with several tens of centimeters of carbon dioxide frost and ice, plus a minor amount of water frost. Details of this process are particularly visible this subimage. The white material is fine grained frost.

The dark, splotchy tones on the dunes may be deposits of particulates deposited from carbon dioxide "geysers" or relatively thick deposits of carbon dioxide ice. The more brownish colors represent defrosted areas. Polygonal patterns on the surface of the dunes are probably cracks in overlying carbon dioxide ice.

Landslides on the dunes' lee slopes are apparent, with a morphology consistent with fluidization from carbon dioxide frost. This and other areas of the north polar region are being investigated by HiRISE to compare to changes in past years.

Photo credit: NASA/JPL/University of Arizona

Landslides in a Terra Cimmeria Crater

The many large landslides inside Valles Marineris are well known, but there are also landslides elsewhere on Mars.

The southwest slope of this crater has at least three landslide lobes. What caused the landslides? They might have formed in the final stage of crater formation, but there are fewer subsequent craters on the lobes than elsewhere on the crater floor, so the landsliding occurred long after the crater's creation.

Perhaps the landslides were triggered by Marsquakes, either due to impact events or to faulting in the crust. Landslides are greatly facilitated by the presence of groundwater, which could have been present at the time these landslides happened, many millions of years ago.

Photo credit: NASA/JPL/University of Arizona

Note: This location is in Terra Cimmeria, to the southeast of Martz Crater.

A Volcanic Pit Chain and Dust Avalanches

This observation shows a volcanic pit chain in Amazonis Planitia.

Associated with two of the pits are meandering channels that splay into distributary patterns to the north. This suggests that the pits are eruptive centers, with the channels carved by lava.

A close-up image shows the eastern wall of the westernmost pit. The fluid-like streaks are the products of dust avalanches, with the dark color resulting from a thin coating of dust that has been removed from the surface.

The upper wall of the pit shows at least four distinct layers, each representing a sequence of one or more lava flows. A hazy, blueish haze bounds the outer circumference of the pit, perhaps resulting from suspended dust. The plains near the pit appear heavily muted, indicating a thick dust cover.

Photo credit: NASA/JPL/University of Arizona

Terraces or Strata on a Crater Slope

This observation shows an interesting layered rock outcrop in the southeast Hellas Region. One of the scientific goals is to look for bedding features that might give clues to what deposited the material: subaerial, subaqueous or polar-ice-like?

Structural features cut through the layered material and strata at this location. Could these features be faults or dikes? Additional images of this region may help us find out.

Photo credit: NASA/JPL/University of Arizona

Eroded Terrain Near Volcanic Fissures

This observation was taken to investigate the topography near the source of fluids from the Cerberus Fossae fractures in the Elysium Planitia region of Mars.

There are distinct channels carved into the terrain here, presumably by floods of water. However, the terrain is coated with lava, and this situation--where flood-eroded channels are completely coated with lava--is seen in many parts of Mars.

This leads some researchers to suggest that the channels were actually carved by the flowing lava, and that there was no flood of water. Images like these are helping to test these ideas.

This is a stereo pair with ESP_026158_1945.

Photo credit: NASA/JPL/University of Arizona

Layered Sediments in Danielson Crater

This crater is named for G. Edward Danielson, Jr. (1939–2005), who was instrumental in the development of a series of Mars cameras, from Mariner 4 launched in 1964 to the Mars Global Surveyor launched in 1996.

These layered sediments are of great interest because they are very regular in thicknesses, suggesting some sort of periodic process such as climate change associated with Mars orbital variations.

Photo credit: NASA/JPL/University of Arizona

Tractus Catena

Tractus Catena is shown here in a computer-generated perspective view. The image was created using data obtained from the High-Resolution Stereo Camera (HRSC) on ESA’s Mars Express spacecraft. The pits seen in the background show hints of layered bedrock in the upper walls of each depression.

Photo credit: ESA/DLR/FU Berlin (G. Neukum)

20 Kilometer Tall Dust Devil in Amazonis Planitia

A dust devil the size of a terrestrial tornado towers above the Martian surface in this late springtime afternoon image of Amazonis Planitia.

Also captured by the Context Camera on MRO, the length of the shadow indicates that the dust plume reached a height of 20 kilometers (12 miles) above the surface! Despite its gargantuan height, the plume is only 70 meters (70 yards) in diameter, giving it a snake-like appearance that is twisted by high altitude winds, similar to another dust devil spotted recently in this region.

Typical tornadoes on Earth are less than 10 miles tall, while dust devils on our planet seldom reach more than a few hundred yards in height. So, why do we classify this plume as a monster dust devil and not a Martian tornado? Dust devils differ from tornadoes in their energy sources. Dust devils are driven by the heat of the surface, absorbed from sunlight and re-radiated to warm the atmosphere. The warm air rises and spins as it contracts, much as a figure skater spins faster as she draws her arms to her sides.

Tornadoes have an additional energy source: the heat given off as water vapor condenses into liquid rain. The condensing water vapor produces the visible part of a tornado, called the condensation funnel, which is made up of water droplets. On Mars, there is too little water vapor in the atmosphere to contribute significantly to atmospheric convection on local scales. The cloud that we see in this image is produced by dust particles, not raindrops. The astounding heights of Martian dust devils are made possible because mass of an atmospheric column on Mars is less than 1 percent than that of a column on Earth. Transfer of heat from the surface into this less dense atmosphere can produce more vigorous convection, which will penetrate higher into the Martian atmosphere than its counterparts do on Earth.

Now, what would happen if you were caught in its path? Because the density of Mars' atmosphere is so low, even a high velocity dust devil is unlikely to knock you over. However, you might be blasted by any sand or dust particles carried along by the dust devil, which might scratch the visor of your space suit quickly if you were caught outside by this monster!

This vortex left behind a bright track as its winds disturbed the dust-covered surface, tracing the path of the dust devil from the northwest towards the southeast. A dust "skirt" twice as wide as the plume itself is seen near the base of the dust devil, but the bright track is the size of the plume and not the skirt. Dozens of smaller dust devils were also spotted in the same Context Camera scene, steadily vacuuming the surface and pumping dust up into the Martian atmosphere.

VIDEO
JPL has produced two excellent animations of this dust devil in action.
Clip 1
Clip 2

Photo credit: NASA/JPL/University of Arizona

Note: For more information, see 12-Mile-High Martian Dust Devil Caught In Act.

Layers in a Crater Wall in Noachis Terra

This image is of the rim of a crater. The Sun is low in the sky (only 15 degrees above the horizon) and shining full on this crater wall (you can see that the area beyond the rim has got long shadows).

The Sun is beautifully illuminating a series of layers exposed in the crater wall which have a variety of different colors.

Note: the subimage is non map-projected, so approximate North is down.

Photo credit: NASA/JPL/University of Arizona

Note: This crater is located in Noachis Terra to the northwest of Argyre Planitia. The closest named crater is Tábor, which is a very short distance to the northwest.

Sedimentary Deposits on the Floor of Ritchey Crater

Ritchey Crater exposes some of the most colorful rock outcrops on Mars in its central peak.

This image reveals comparable diversity in some of the layered sediments and jumbled deposits (megabreccia) on the crater floor. In general the blues and greens indicate unaltered minerals like olivine and pyroxene whereas the warmer colors indicate altered minerals such as clays.

Photo credit: NASA/JPL/University of Arizona

Elephantine Lava Flow in Elysium Planitia

This observation highlights terrain that looks like an elephant. This is a good example of the phenomena "pareidolia," where we see things (such as animals) that aren't really there.

Actually, this image covers the margin of a lava flow in Elysium Planitia, the youngest flood-lava province on Mars. Flood lavas cover extensive areas, and were once thought to be emplaced extremely rapidly, like a flood of water.

Most lava floods on Earth are emplaced over years to decades, and this is probably true for much of the lava on Mars as well. An elephant can walk away from the slowly advancing flow front. However, there is also evidence for much more rapidly flowing lava on Mars, a true flood of lava. In this instance, maybe this elephant couldn't run away fast enough.

Note: the subimage is not map-projected, so approximate North is down.

Photo credit: NASA/JPL/University of Arizona

Note: This site is located in Phlegra Dorsa; the closest named impact crater is Lockyer, which is some distance off to the west.

Cratered Dune Forms in Melas Chasma

One of the scientific goals for taking this observation is to create a stereo pair with another HiRISE image. From stereo pairs, which are pictures of the same area but at different angles, HiRISE creates 3D or anaglyph pictures.

Known since at least 2003, this is a wonderful case of aeolian sandstone that (a) preserves its original sand dune bedform shapes and (b) lies unconformably over a previously-eroded surface of layered sedimentary rock.

Photo credit: NASA/JPL/University of Arizona

Note: This site is located on the southern wall of Melas Chasma.

Lava Lamp Terrain on the Floor of Hellas Basin

Some of the weirdest and least-understood landscapes on Mars are on the floor of the deep Hellas impact basin. This image was acquired in northwest Hellas where depths are more than 6 kilometers below the reference (or roughly the average) altitude for Mars.

There are what look like impact craters but are elongated, as if stretched in a viscous manner (like in a lava lamp). Some of the flowing landforms are similar to those elsewhere in the middle latitudes of Mars, where the Shallow Radar (SHARAD) experiment on MRO has detected ice, but no ice detection has been reported here.

The floor of Hellas is relatively poorly mapped because it is often obscured by dust and haze in the atmosphere.

Photo credit: NASA/JPL/University of Arizona

Late Spring in Vastitas Borealis

These dark sand dunes in the north polar region, basking in the sunshine of late spring, have shed most of their seasonal layer of winter ice.

A few bright ice deposits remain sequestered in "cold traps" shadowed from the Sun on the poleward-facing side of the dunes. Some bright patches of ice at the foot of the sunlit side of the dunes may be places where ice slumped to the foot of the dune creating a longer-lasting snow bank.

Photo credit: NASA/JPL/University of Arizona

Note: The closest named crater to this site is Escorial Crater, which is some distance off to the northeast; the closest named feature is Abalos Colles, which is also to the northeast, although not nearly as far away.

Jumbled Rocks Near Nili Fossae

This image covers a region of Mars near Nili Fossae that contains some of the best exposures of ancient bedrock on Mars.

The enhanced-color subimage shows part of the ejecta from an impact crater. The impact broke up already diverse rocks types and mixed them together to create this wild jumble of colors, each representing a different type of rock.

Photo credit: NASA/JPL/University of Arizona

Note: The above image is slightly smaller in size (2048 x 1536 px) than what is normally posted on this blog (2560 x 1920 px) due to the fact that the larger image is over the allowable download size for photos onto Blogger.

Mineral Veins in Terra Sabaea

The bright linear features cutting the bedrock in the center region of this image look like mineral veins.

Mineral veins are sheetlike bodies of minerals formed by water that flows through fractures. The setting of this image is the central uplift of a large (approximately 50-kilometer diameter) impact crater, where deep, ancient bedrock was uplifted about 5 kilometers and fractured. Heat from the impact melted ice in the Martian crust, creating a hydrothermal system. This could have been a habitable environment.

A small mineral vein was recently discovered by the Opportunity rover at Endeavour Crater.

This is a stereo pair with ESP_025766_2005.

Photo credit: NASA/JPL/University of Arizona

Note: This crater is located in northeast Terra Sabaea, in a complex of craters southeast of Baldet Crater.

Boulders on the Floor of Hellas Planitia

This image reveals bouldery patches on the floor of the giant Hellas impact basin.

The boulders are often crudely aligned. Maybe these boulders were deposited or sculpted by flowing ice in the form of glaciers.

Photo credit: NASA/JPL/University of Arizona

Magical Mystery Mound

How exactly these strange landforms came to be is a mystery. It probably isn't magical, but the catchy Beatles-era title did get you to read this caption.

The contorted material sits on the floor of a degraded impact crater. It has some bizarrely grooved textures that show up nicely with the low-sun illumination (with the Sun approximately 7 degrees above the horizon). We've seen this texture elsewhere on Mars, so a systematic study might lead to a good hypothesis about its origin.

The color data reveals some bluish material-- seasonal frost that is just starting to accumulate here in late fall.

Photo credit: NASA/JPL/University of Arizona

Note: The crater where this mound is located is in Noachis Terra, very close to Asimov Crater, to the northwest, and Maunder Crater, due west.

A Cloudy Day Over Vastitas Borealis

Mars occasionally has cloudy weather. We intended to take a picture of the bright ice-covered dunes that are faintly visible through these thin clouds, but weather forecasting on Mars is just as challenging as on Earth.

Where the clouds are thin, the remaining bright winter ice is visible, protected in shallow grooves on the ground, in addition to covering the dunes.

Photo credit: NASA/JPL/University of Arizona

Note: And, no, that is not the Face on Mars. ;) Although it does remind me more of those moai (statues) on Easter Island.

The Serpent Dust Devil of Mars

A towering dust devil casts a serpentine shadow over the Martian surface in this stunning, late springtime image of Amazonis Planitia.

The length of the shadow indicates that the dust plume reaches more than 800 meters, or half a mile, in height. The tail of the plume does not trace the path of the dust devil, which had been following a steady course towards the southeast and left a bright track behind it.

The delicate arc in the plume was produced by a westerly breeze at about a 250-meter height that blew the top of the plume towards the east. The westerly winds and the draw of warmth to the south combine to guide dust devils along southeast trending paths, as indicated by the tracks of many previous dust-devils. The dust plume itself is about 30 meters in diameter.

Numerous bright tracks trend from northwest to southeast. It is interesting to see that these tracks are bright, whereas dust-devil tracks elsewhere on Mars are usually dark. Dark tracks are believed to form where bright dust is lifted from the surface by dust devils, revealing a darker substrate.

Here in Amazonis, the dust cover is too thick to be penetrated by such scouring. A blanket of bright dust was deposited over this region recently, just before the arrival of MRO, so the surface dust here can still be moved. Perhaps the bright tracks form when the settled dust is stirred up by the strong winds generated by the dust devils (tangential wind speeds of up to 70 miles per hour have been recorded in HiRISE images of other dust devils).

It's also interesting that this image was taken during the time of year when Mars is farthest from the Sun. Just as on Earth, Martian winds are powered by solar heating. Exposure to the Sun's rays should be at a minimum during this season, yet even now, dust devils act relentlessly to clean the surface of freshly deposited dust, a little at a time.

This is a stereo pair with ESP_025985_2160.

Photo credit: NASA/JPL/University of Arizona

Note: For a short video showing how the dust devil would look like from the ground, see Storm Chaser on Mars.

Icy Flows in Fitzroy Crater

This image shows flow features (tongue-shaped features in the depressions running down the slope) on the inner slope of an impact crater east of Hellas impact basin.

The time of year combined with MRO's orbit and the slope combine to provide the geometry for an image with almost glancing (very low sun) illumination. Such low-sun lighting enhances subtle topographic features and makes a dramatic image.

Other flows in this region of Mars, long thought to be due to flowing ice, have been confirmed to be icy by the Shallow Radar (SHARAD) experiment on MRO.

Photo credit: NASA/JPL/University of Arizona

Note: These ice flows are in Fitzroy crater.

Layers of Water-Deposited Sediment

This image covers part of the floor of a large ancient impact crater, near the western rim.

The subimage shows layered deposits, many with distinct colors (the colors are enhanced or exaggerated). These layers have a morphology similar to that seen elsewhere on Mars in obvious alluvial fans where channels emerge into craters.

In this case the channels are not obvious, but we suspect that it is the same kind of deposit and the ancient channel is not well preserved due to subsequent modification.

Photo credit: NASA/JPL/University of Arizona

Note: This impact crater is located in Xanthe Terra just to the northeast of Mutch Crater.

Slope Streak Stripes on Crater Walls

Radially-oriented slope streaks paint stripes on the sides of this crater in Arabia Terra. Slope streaks are common features on steep slopes in Mars' dusty terrain, but this crater is a particularly dramatic example.

Slope streaks, thought to be the result of shallow cascades of dust, are dark when fresh and fade as they age (see this highly stretched subimage that emphasizes the color difference between streaks). So it is clear that this crater experienced repeated episodes of streak formation, apparently around its entire circumference.

Other steep slopes nearby also show evidence of repeated slope streak activity - see ESP_024924_1945, PSP_009272_1955, and PSP_008705_1950 - but none are quite as photogenic as this one!

Photo credit: NASA/JPL/University of Arizona

Note: This crater is near the western border of Terra Sabaea, with Meridiani Planum lying to the southwest. The closest named feature is Gill Crater, to the west.

Syrtis Major

Syrtis Major, discovered in 1659 by Christaan Huygens, is a volcanic province on Mars. The image is centered on approximately 16°N/73°E. The High-Resolution Stereo Camera on ESA’s Mars Express collected the data for these images on 8 June 2011 during orbit 9487. The images have a ground resolution of approximately 19 m per pixel. This perspective view has been calculated from the Digital Terrain Model derived from the stereo channels. Some ancient lava flow fronts are seen in the foreground and a lighter-toned butte is emerging on the right.

Photo credit: ESA/DLR/FU Berlin (G. Neukum)

Note: For more information, see Mars Express Reveals Wind-Blown Deposits on Mars.

Phlegra Montes

Phlegra Montes is a range of gently curving mountains and ridges on Mars. They extend from the northeastern portion of the Elysium volcanic province to the northern lowlands. The High-Resolution Stereo Camera on ESA’s Mars Express collected the data for these images on 1 June 2011 during orbit 9465. The image combines data from the nadir channel and one stereo channel to produce this 3D image. Stereoscopic glasses are required to see the 3D effect.

Photo credit: ESA/DLR/FU Berlin (G. Neukum)

Note: For more information, see Mountains and Buried Ice on Mars.

Tenth Anniversary Image from Themis

The Thermal Emission Imaging System (THEMIS) camera on NASA's Mars Odyssey spacecraft has completed an unprecedented full decade of observing Mars from orbit.

THEMIS captured this image on February 19, 2012, 10 years to the day after the camera recorded its first view of Mars. This image covers an area 11 by 32 miles (19 by 52 kilometers) in the Nepenthes Mensae region north of the Martian equator. The view depicts a knobby landscape where the southern highlands are breaking up as the terrain descends into the northern lowlands.

Odyssey, launched in 2001, has worked at Mars longer than any mission in history.

Photo credit: NASA/JPL-Caltech/ASU

Comparison of Earth's Interior with Mars and the Moon

Mars has the same basic internal structure as the Earth and other terrestrial (rocky) planets. It is large enough to have pressures equivalent to those throughout the Earth's upper mantle, and it has a core with a similar fraction of its mass. This diagram shows the depths at which high pressures cause certain minerals to transform to higher-density crystal structures. In contrast, the pressure even near the center of the Moon barely reach that just below the Earth's crust and it has a tiny, almost negligible core. The size of Mars indicates that it must have undergone many of the same separation and crystallization processes that formed the Earth's crust and core during early planetary formation.

Illustration credit: JPL/NASA

Well-Speckled Polar Dunes

These barchan (crescent-shaped) sand dunes are found within the North Polar erg of Mars. This type of dune provides a great record of the wind environment when they formed and moved: barchan dunes' horns point downwind. Although the question of present-day sand motion is still open, it appears possible that these dunes are active (when not covered in frost) as their crestlines are very sharp and their slipfaces (the inner curved region between the horns/downwind surface) appears very smooth and steep.

In this image, taken during the northern spring season, the dunes and ground are still covered in seasonal frost. The speckled appearance is due to the warming of the area -- as the carbon dioxide frost and ice on the dunes warms, small areas warm and sublimate (turn from solid to gas) faster, creating small jets that expose/deposit dark sand and dust onto the surface. Notice that there are no spots on the ground between the dunes -- that is because the ground stays more uniformly cold, unlike the darker dune sand.

As spring continues, more spots will appear on the dunes until, suddenly, all of the frost on the dunes and ground will be gone and the dark dune sand will be exposed until next winter.

Photo credit: NASA/JPL/University of Arizona

Note: This image is located in Olympia Mensae.

Utopia Planitia Scallops, Polygons, and Boulders

This terrain is covered by pits and scallops (pits open on one side), perhaps due to collapse after sublimation of subsurface ice.

This full-resolution anaglyph sample shows that the surface is cut into many polygons about 10 meters wide, that form as ice expands and contracts with temperature changes. There are also many meter-scale boulders on the surface, which must be rocks rather than blocks of ice, or they would not be stable on the surface.

More than 10 meters thickness of ice must have sublimated from some areas. (Sublimation is the process of going from a solid directly to a gas). How did the ice get deposited? One idea is that it's from snowfall (in a different climate), but then it is difficult to explain the presence of the boulders. The other possibility is transport through the shallow subsurface in very thin films of water over many years.

This is a stereo pair with ESP_025277_2275.

Photo credit: NASA/JPL/University of Arizona

Note: This image is located in northwestern Utopia Planitia; the closest named feature is Nier Crater, which is some distance off to the southeast.

Dunes in Late Fall: Frost in the Ripples

These dunes in Aonia Terra are being monitored for changes such as gullies, which form over the winter from the action of carbon dioxide frost.

The season in which this image was acquired was late fall in the Southern hemisphere. Frost is just starting to accumulate here, and is concentrated on pole-facing slopes and in the troughs between the meter-scale ripples.

The colors have been enhanced in the subimage.

Photo credit: NASA/JPL/University of Arizona

Imaging in Deep Shadows

This image of an impact crater in Terra Cimmeria was acquired when the Sun was just 11 degrees above the horizon, so a long shadow extends over most of the crater interior.

However, there is still diffuse illumination from the sky and HiRISE has the ability to acquire sufficient signal over faint targets to make useful images. The subimage shows an area entirely in shadow, but with pixel values "stretched" to show the detail.

The crater interior shows a pattern of ridges and mounds suggestive of icy flow, which is common at this latitude on Mars.

Photo credit: NASA/JPL/University of Arizona

Search for the Mars 6 Lander

The Soviet Mars 6 lander arrived at Mars on 12 March 1974. The descent module entered the atmosphere and the parachute opened at 09:08:32 UT--the craft was collecting and returning data.

Contact with the descent module was lost at 09:11:05 UT, about when expected to encounter the surface.

Because we know that the parachute opened and have some idea where it was headed, we have a chance of locating the hardware on the surface with HiRISE. In fact, an anomalous small bright patch was seen by MRO's Context Camera (CTX) team, which a CTX team member then suggested as a target for HiRISE.

The bright parachutes were the easiest thing to spot on the ground at 5 of the 6 past successful landing sites. In this subimage we see the bright spot at full HiRISE resolution, and it appears to be a patch of relatively bright bedrock, with a pattern of thin lines (fractures) typical of such outcrops.

We'll keep trying to find this and other failed landers, but there is a lot of surface area to cover on Mars and the hardware may be covered by dust and look much like natural features on Mars.

Photo credit: NASA/JPL/University of Arizona

Note: This location is on the border between southern Margaritifer Terra and northern Noachis Terra, to the northeast of Argyre Planitia.

Opportunity's Self-Portrait

This self portrait from NASA's Mars Exploration Rover Opportunity shows dust accumulation on the rover's solar panels as the mission approached its fifth Martian winter. The dust reduces the rover's power supply, and the rover's mobility is limited until the winter is over or wind cleans the panels.

This is a mosaic of images taken by Opportunity's panoramic camera (Pancam) during the 2,111th to 2,814th Martian days, or sols, of the rover's mission (December 21 to December 24, 2011). The downward-looking view omits the mast on which the camera is mounted.

The portrait combines exposures taken through Pancam filters centered on wavelengths of 601 nanometers, 535 nanometers and 482 nanometers. It is presented in approximate true color, the camera team's best estimate of what the scene would look like if humans were there and able to see it with their own eyes.

Earlier panoramas of Opportunity's deck provide comparison for the dust deposition: sols 322-323 PIA07372, sols 652-663 PIA03271 and sols 1282-1284 PIA15114.

Opportunity has worked through four Martian southern hemisphere winters since it landed in in January 2004 about 14 miles (23 kilometers) northwest of its current location. Closer to the equator than its twin rover, Spirit, Opportunity has not needed to stay on a Sun-facing slope during the previous winters. Now, however, Opportunity's solar panels carry a thicker coating of dust, and the team is using a strategy employed for three winters with Spirit: staying on a Sun-facing slope. The Sun will pass relatively low in the northern sky from the rover's perspective for several months of shortened daylight before and after the southern Mars winter solstice on March 30, 2012. Opportunity is conducting research while located on the north-facing slope of a site called "Greeley Haven."

Photo credit: NASA/JPL-Caltech/Cornell/Arizona State University

Uplifted Jumble of Ancient Bedrock

Impact craters larger than a certain size have complex forms, including central peaks or other structures that result from structural uplift of the target material. This provides a mechanism for exposing deep, ancient bedrock.

The enhanced-color subimage shows a great variety of colors and textures in the bedrock, where it is exposed from beneath a dark fine-grained mantle. The mantle is sometimes modified by the wind into dunes.

The bedrock here includes massive, layered, and broken-up (brecciated) areas. This crater is located in the volcanic plains between Argyre Planitia and Valles Marineris.

Photo credit: NASA/JPL/University of Arizona

Note: This crater is located in northwestern Noachis Terra, to the east of Nectaris Fossae. It is also located northwest of Ritchey Crater.

Bedrock Exposures in an Acidalia Planitia Crater Wall

This mid-latitude (53 degrees North) crater appears well-preserved, with a clear ejecta blanket and well-defined rim. Bedrock exposures are visible near the top of the rim. Studying this site can yield information about the underlying terrain within this region.

Additionally, HiRISE images show small-scale features formed through modification and degradation processes; for example, few-meter-wide cracks that run perpendicular to the slope are likely formed through slumping and periglacial processes.

Gullies and flow features are also likely to be found along the crater wall -- possible shallow channels starting at the bedrock exposures are visible in along the rim in the upper/left portion of the image.

Photo credit: NASA/JPL/University of Arizona

Note: This crater is located in Acidalia Planitia, to the northwest of Lyot Crater.

Polar Layers in Gemini Scopuli

This is an especially pretty image due to the color variations and lighting geometry.

The color variations are due to mixtures of reddish dust with white frost and ice. The image was acquired as a "rider" with either a Context Camera or CRISM target.

One of these other MRO experiments chose this location to point at with the spacecraft, then the HiRISE science lead for this 2-week planning cycle decided to add a HiRISE image here for a high-resolution sample.

Photo credit: NASA/JPL/University of Arizona

Note: This image is located along one of the canyons in the Gemini Scopuli region of Planum Boreum.