The original "Exploration of Mars" topic became excessively long. As a result the topic has been split into individual, mission based, topics. The "Exploration of Mars" topic is now for news and discoveries not specific to any one mission.

Links to the other topics can be found below:

• Mars Reconnaissance Orbiter
  
• Mars Odyssey
  
• Mars Express
  
• Mars Global Surveyor
  
• Mars Phoenix Lander
  
• Exploration of Mars
  
• Mars Science Laboratory

Waspie_Dwarf






While driving eastward toward the northwestern flank of "McCool Hill," the wheels of NASA's Mars Exploration Rover Spirit churned up the largest amount of bright soil discovered so far in the mission. This image from Spirit's panoramic camera (Pancam), taken on the rover's 788th Martian day, or sol, of exploration (March 22, 2006), shows the strikingly bright colors and large extent of the materials uncovered.

Several days earlier, Spirit's wheels unearthed a small patch of light-toned material informally named "Tyrone." In images from Spirit's panoramic camera, "Tyrone" strongly resembled both "Arad" and "Paso Robles," two patches of light-toned soils discovered earlier in the mission. Spirit found "Paso Robles" in 2005 while climbing "Cumberland Ridge" on the western slope of "Husband Hill." In early January 2006, the rover discovered "Arad" on the basin floor just south of "Husband Hill." Spirit's instruments confirmed that those soils had a salty chemistry dominated by iron-bearing sulfates. Spirit's Pancam and miniature thermal emission spectrometer examined this most recent discovery, and researchers will compare its properties with the properties of those other deposits.

These discoveries indicate that salty, light-toned soil deposits might be widely distributed on the flanks and valley floors of the "Columbia Hills" region in Gusev Crater on Mars. The salts, which are easily mobilized and concentrated in liquid solution, may record the past presence of water. So far, these enigmatic materials have generated more questions than answers, however, and as Spirit continues to drive across this region in search of a safe winter haven, the team continues to formulate and test hypotheses to explain the rover's most fascinating recent discovery.


Click on image for high resolution version.

This view is an approximately true-color rendering that combines separate images taken through the Pancam's 753-nanometer, 535-nanometer, and 432-nanometer filters.

Image credit: NASA/JPL-Caltech/Cornell

Bright Soil Near 'McCool' (False Color)


Click on image for high resolution version.

This image is a false-color rendering using using Pancam's 753-nanometer, 535-nanometer, and 432-nanometer filters.

Image credit: NASA/JPL-Caltech/Cornell

Bright Soil Near 'McCool' (3-D)


Click on image for high resolution version.

This stereo view combines images from the two blue (430-nanometer) filters in the Pancam's left and right "eyes." The image should be viewed using red-and-blue stereo glasses, with the red over your left eye.

Image credit: NASA/JPL-Caltech/Cornell



Source: NASA/JPL - Mars Exploration Rovers - Spirit

looks like nevada

I don't know about nevada, but that looks wicked. great pics

Waspie, you indeed have a great fascination of the beauties of space

Amazing images!

Coarse Layering at 'Home Plate'


Click on image for high resolution version.

This image shows coarse-grained layers from around the edge of a low plateau called "Home Plate" inside Mars' Gusev Crater. One possible origin is material falling to the ground after being thrown aloft by an explosion such as a volcanic eruption or meteorite impact.

The panoramic camera (Pancam) on NASA's Mars Exploration Rover Spirit acquired the exposures for this image on Spirit's 749th Martian day (Feb. 10, 2006). This view is an approximately true-color rendering mathematically generated from separate images taken through all of the left Pancam's 432-nanometer to 753-nanometer filters.

Image credit: NASA/JPL/Cornell

'Home Plate' Evidence for an Explosive Past


Click on image for high resolution version.

This view of layers around the edge of a low plateau called "Home Plate" inside Mars' Gusev Crater includes a feature that may be what geologists call a "bomb sag" and interpret as evidence of an explosive event, such as a volcanic eruption.

The layers seen here are generally straight and parallel except in the lower right, where they dip around a greyish rock that is about 4 centimeters (about 1.5 inches) in diameter. When layered deposits are struck by a falling rock while the layers are still soft, this type of pattern can be created. The rock might have been lofted by a volcanic burst or as part of the material ejected by the crater-forming impact of a meteorite.

The panoramic camera (Pancam) on NASA's Mars Exploration Rover Spirit acquired the exposures for this image on Spirit's 754th Martian day (Feb. 15, 2006). This view is an approximately true-color rendering mathematically generated from separate images taken through all of the left Pancam's 432-nanometer to 753-nanometer filters.

Image credit: NASA/JPL/Cornell

Source: NASA/JPL - Mars Exploration Rovers - Spirit

Click on image for high resolution version.

The stack of fine layers exposed at a ledge called "Payson" on the western edge of "Erebus Crater" in Mars' Meridiani Planum shows a diverse range of primary and secondary sedimentary textures formed billions of years ago. These structures likely result from an interplay between windblown and water-involved processes.

The panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity acquired the exposures for this image on Spirit's 749th Martian day (Feb. 10, 2006). This view is an approximately true-color rendering mathematically generated from separate images taken through all of the left Pancam's 432-nanometer to 753-nanometer filters.

Image credit: NASA/JPL/Cornell

Source: NASA/JPL - Mars Exploration Rovers - Opportunity

NASA's Mars rover Spirit has reached a safe site for the Martian winter, while its twin, Opportunity, is making fast progress toward a destination of its own.

The two rovers recently set out on important -- but very different -- drives after earlier weeks inspecting sites with layers of Mars history. Opportunity finished examining sedimentary evidence of ancient water at a crater called "Erebus," and is now rapidly crossing flat ground toward the scientific lure of a much larger crater, "Victoria."


Image above: This image from Spirit shows coarse-grained layers from
around the edge of a low plateau called "Home Plate" inside Mars' Gusev
Crater. Image Credit: NASA/JPL/Cornell
+ Full image and caption

Spirit studied signs of a long-ago explosion at a bright, low plateau called "Home Plate" during February and March. Then one of its six wheels quit working, and Spirit struggled to complete a short advance to a north-facing slope for the winter. "For Spirit, the priority has been to reach a safe winter haven," said Dr. Steve Squyres of Cornell University, Ithaca, N.Y., principal investigator for the Mars Exploration Rover project.

The rovers have operated more than eight times as long as their originally planned three-month explorations on Mars. Each has driven more than 6.8 kilometers (4.2 miles) about 11 times as far as planned. Combined, they have returned more than 150,000 images. Two years ago, the project had already confirmed that at least one place on Mars had a wet and possibly habitable environment long ago. The scientific findings continue.

Opportunity spent most of the past four months at Erebus, a highly eroded impact crater about 300 meters (1,000 feet) in diameter, where the rover found extensive exposures of thin, rippled layering interpreted as a fingerprint of flowing water. "What we see at Erebus is a thicker interval of wetted sediment than we've seen anywhere else," said Dr. John Grotzinger of the California Institute of Technology, "The same outcrops also have cracks that may have formed from wetting and drying."

In mid-March, Opportunity began a 2-kilometer (1.6-mile) trek from Erebus to Victoria, a crater about 800 meters (half a mile) across, where a thick sequence of sedimentary rocks is exposed. In the past three weeks, Opportunity has already driven more than a fourth of that distance.

At Home Plate, Spirit found coarse layering overlain by finer layering in a pattern that fits accumulation of material falling to the ground after a volcanic or impact explosion. In one place, the layers are deformed where a golfball-size rock appears to have fallen on them while they were soft. "Geologists call that a 'bomb sag,' and it is strong evidence for some kind of explosive origin," Squyres said. "We would like to have had time to study Home Plate longer, but we needed to head for a north-facing slope before winter got too bad."

Spirit is in Mars' southern hemisphere, where the sun is crossing lower in the northern sky each day. The rovers rely on solar power. The amount available will keep dropping until the shortest days of the Mars winter, four months from now. To keep producing enough electricity to run overnight heaters that protect vital electronics, Spirit's solar panels must be tilted toward the winter sun by driving the rover onto north-facing slopes. However, on March 13 the right-front wheel's drive motor gave out. Spirit has subsequently driven about 80 meters (262 feet) using five wheels and dragging the sixth, but an initial route toward a large hill proved impassable due to soft ground. Last week, the team chose a smaller nearby ridge, dubbed "Low Ridge Haven," as the winter destination. Spirit reached the ridge Sunday and has a favorable 11-degree tilt toward the north.

"We have to use care choosing the type of terrain we drive over," Dr. Ash**ey Trebi-Ollennu, a rover planner at NASA's Jet Propulsion Laboratory, Pasadena, Calif., said about the challenge of five-wheel driving. In tests at JPL, the team has been practicing a maneuver to gain additional tilt by perching the left-front wheel on a basketball-size rock.

Spending eight months or so at Low Ridge Haven will offer time for many long-duration studies that members of the science team have been considering since early in the mission, said Dr. Ray Arvidson of Washington University in St. Louis, deputy principal investigator. These include detailed mapping of rocks and soils; in-depth determination of rock and soil composition; monitoring of clouds and other atmospheric changes; watching for subtle surface changes due to winds; and learning properties of the shallow subsurface by tracking surface-temperature changes over a span of months.

JPL, a division of the California Institute of Technology, Pasadena, manages the Mars Exploration Rover Project for the NASA Science Mission Directorate.

For images and information about the rovers, see www.nasa.gov/rovers or http://marsrovers.jpl.nasa.gov . For information about NASA and agency programs on the Web, visit www.nasa.gov .


Media contact:Guy Webster (818) 354-6278
Jet Propulsion Laboratory, Pasadena, Calif.

Dwayne Brown/Erica Hupp (202) 358-1726/1237
NASA Headquarters, Washington

2006-054

Source: NASA - Mars - Missions

anymore news

SPIRIT UPDATE: Spirit Finally Reaches a Potential Winter Haven
- sol 803-811, Apr 14, 2006:

Spirit is basking in the sun, relatively speaking, on a 10.8-degree, north-facing slope in Gusev Crater on Mars. After turning away from the rover's previous heading toward "McCool Hill" last week, Spirit started driving toward a nearby area known as "Low Ridge Haven" and arrived there over the weekend. Because rover drivers were able to get Spirit to a place where the solar panels tilt more steeply toward the sun, the rover's power output increased by 50 to 60 watt-hours per sol (a sol is one day on Mars). That gives the rover enough energy for about one hour of daytime remote science.

So far in this location, Spirit has collected a 360-degree panorama with the navigation camera, a smaller panorama with the panoramic camera, two targeted observations with the miniature thermal emission spectrometer, and five targeted images with the panoramic camera. Spirit also collected data with instruments on the robotic arm, including the microscopic imager, the alpha particle X-ray spectrometer, and the Mössbauer spectrometer. All the rock and soil targets in this area are being informally named after Antarctic research stations and explorers.

Source: NASA/JPL - Rover Status - Spirit

Click on image for high resolution version.

As NASA's Mars Exploration Rover Opportunity continues a southward trek from "Erebus Crater" toward "Victoria Crater," the terrain consists of large sand ripples and patches of flat-lying rock outcrops, as shown in this image. Whenever possible, rover planners keep Opportunity on the "pavement" for best mobility.

This false-color image mosaic was assembled using images acquired by the panoramic camera on Opportunity's 784th sol (April 8, 2006) at about 11:45 a.m. local solar time. The camera used its 753-nanometer, 535-nanometer and 432-nanometer filters. This view shows a portion of the outcrop named "Bosque," including rover wheel tracks, fractured and finely-layered outcrop rocks and smaller, dark cobbles littered across the surface.

Image credit: NASA/JPL-Caltech/Cornell

Source: NASA/JPL - Mars Exploration Rovers - Opportunity

At least three different kinds of rocks await scientific analysis at the place where NASA's Mars Exploration Rover Spirit will likely spend several months of Martian winter. They are visible in this picture, which the panoramic camera on Spirit acquired during the rover's 809th sol, or Martian day, of exploring Mars (April 12, 2006). Paper-thin layers of light-toned, jagged-edged rocks protrude horizontally from beneath small sand drifts; a light gray rock with smooth, rounded edges sits atop the sand drifts; and several dark gray to black, angular rocks with vesicles (small holes) typical of hardened lava lie scattered across the sand.



Scans Winter Haven


Click on image for high resolution version.

This view is an approximately true-color rendering that combines images taken through the panoramic camera's 753-nanometer, 535-nanometer, and 432-nanometer filters.

Image credit: NASA/JPL-Caltech/Cornell



Scans Winter Haven (False Color)


Click on image for high resolution version.

This view is a false-color rendering that combines images taken through the panoramic camera's 753-nanometer, 535-nanometer, and 432-nanometer filters.

Image credit: NASA/JPL-Caltech/Cornell

Source: NASA/JPL - Mars Exploration Rovers - Spirit

In time to survive the Martian winter, NASA's Mars Exploration Rover Spirit has driven to and parked on a north-facing slope in the "Columbia Hills." This vantage point will optimize solar power during the upcoming winter season and maximize the vehicle's ability to communicate with the NASA Odyssey orbiter.

Top science priorities for the coming months are a detailed, 360-degree panorama using all 13 filters of the panoramic camera, a study of surface and subsurface soil properties, and monitoring of the atmosphere and its changes. The planned subsurface soil experiments will be a first for the Mars Exploration Rover mission. To conduct the study, Spirit will use the brush on the rock abrasion tool to carefully sweep away soil, much the way an archaeologist uses a brush to uncover artifacts. At each level, Spirit will measure the mineral and chemical properties and assess the physical nature (such as grain size, texture, hardness) of the material, using the Athena science instruments on the robotic arm. Of particular interest are vertical variations in soil characteristics that may indicate water-related deposition of sulfates and other minerals.

Panoramic images will provide important information about the nature and origin of surrounding rocks and soils. Spirit will also study the mineralogy of the surrounding terrain using the thermal emission spectrometer and search for surface changes caused by high winds. After the winter solstice in August, depending on energy levels, scientists may direct the rover to pivot around the disabled, right front wheel to get different targets within reach of the arm. When the winter season is over and solar energy levels rise again, scientists will direct Spirit to leave its winter campaign site and continue examining the "Columbia Hills."

Spirit acquired the images in this mosaic with the navigation camera on the rover's 807th Martian day, or sol, of exploring Gusev Crater on Mars (April 11, 2006). Approaching from the east are the rover's tracks, including a shallow trench created by the dragging front wheel. On the horizon, in the center of the panorama, is "McCool Hill." This view is presented in a cylindrical projection with geometric seam correction.

Image credit: NASA/JPL-Caltech

Source: NASA/JPL - Mars Exploration Rovers - Spirit

A spectacular field of Martian sand ripples separates NASA's Mars Exploration Rover Spirit from the slopes of "Husband Hill." It has been 200 Martian days, or sols, since the rover started a descent from the top of the peak to the rover's current position on "Low Ridge." Looking back to the north on sol 813 (April 17, 2006), Spirit acquired this blue-filter (436-nanometer) view with the right panoramic camera (Pancam) while the Sun was low in the sky late in the afternoon. Because of the low-angle lighting (sunlight is coming from the left), images like this provide superb views of subtle textures in the topography both near and far. Husband Hill, where the rover was perched late last summer, rises prominently just left of center in this view. A 150-meter wide (500 foot) field of curving sand ripples named "El Dorado" lies at the base of Husband Hill.

By collecting photos like this at different times of day, when lighting comes from different directions, scientists can distinguish surface properties such as color and reflectivity from topography and roughness. By separating these components they can map more details of the geologic terrain, providing new clues about the geologic history of Gusev Crater.

Image credit: NASA/JPL-Caltech/Cornell

Source: NASA/JPL - Mars Exploration Rovers - Spirit

NASA's Mars Exploration Rover Opportunity continues to cut southward across a plain marked by large sand ripples and a pavement of outcrop rock. The ripple in the center of the image shows a distinct pattern of banding, which the science team hopes to investigate more closely during the trek through this terrain. The banding and other features have inspired a hypothesis that Meridiani ripples are old features that are currently being eroded, and not transported, by wind. This navigation camera image was taken on Opportunity's sol 795, April 19, 2006.

Image credit: NASA/JPL-Caltech

Source: NASA/JPL - Mars Exploration Rovers - Opportunity

Spirit Beholds Bumpy Boulder

05.05.06

As NASA's Mars Exploration Rover Spirit began collecting images for a 360-degree panorama of new terrain, the rover captured this view of a dark boulder with an interesting surface texture. The boulder sits about 40 centimeters (16 inches) tall on Martian sand about 5 meters (16 feet) away from Spirit. It is one of many dark, volcanic rock fragments -- many pocked with rounded holes called vesicles -- littering the slope of "Low Ridge." The rock surface facing the rover is similar in appearance to the surface texture on the outside of lava flows on Earth.

Spirit took this approximately true-color image with the panoramic camera on the rover's 810th sol, or Martian day, of exploring Mars (April 13, 2006), using the camera's 753-nanometer, 535-nanometer, and 432-nanometer filters.

Image Credit: NASA/JPL-Caltech/Cornell/NMMNH

+ High resolution JPEG

Source: NASA - Missions - MER

Spirit Beholds Bumpy Boulder (False Color)

05.05.06

As NASA's Mars Exploration Rover Spirit began collecting images for a 360-degree panorama of new terrain, the rover captured this view of a dark boulder with an interesting surface texture. The boulder sits about 40 centimeters (16 inches) tall on Martian sand about 5 meters (16 feet) away from Spirit. It is one of many dark, volcanic rock fragments -- many pocked with rounded holes called vesicles -- littering the slope of "Low Ridge." The rock surface facing the rover is similar in appearance to the surface texture on the outside of lava flows on Earth.

Spirit took this false-color image with the panoramic camera on the rover's 810th sol, or Martian day, of exploring Mars (April 13, 2006). This image is a false-color rendering using camera's 753-nanometer, 535-nanometer, and 432-nanometer filters.

Image Credit: NASA/JPL-Caltech/Cornell/NMMNH

+ High resolution JPEG

Source: NASA - Missions - MER

This pair of images from the panoramic camera on NASA's Mars Exploration Rover Opportunity served as initial confirmation that the two-year-old rover is within sight of "Victoria Crater," which it has been approaching for more than a year.

Engineers on the rover team were unsure whether Opportunity would make it as far as Victoria, but scientists hoped for the chance to study such a large crater with their roving geologist. Victoria Crater is 800 meters (nearly half a mile) in diameter, about six times wider than "Endurance Crater," where Opportunity spent several months in 2004 examining rock layers affected by ancient water.

When scientists using orbital data calculated that they should be able to detect Victoria's rim in rover images, they scrutinized frames taken in the direction of the crater by the panoramic camera. To positively characterize the subtle horizon profile of the crater and some of the features leading up to it, researchers created a vertically-stretched image (top) from a mosaic of regular frames from the panoramic camera (bottom), taken on Opportunity's 804th Martian day (April 29, 2006).

The streched image makes mild nearby dunes look like more threatening peaks, but that is only a result of the exaggerated vertical dimension. This vertical stretch technique was first applied to Viking Lander 2 panoramas by Philip Stooke, of the University of Western Ontario, Canada, to help locate the lander with respect to orbiter images. Vertically stretching the image allows features to be more readily identified by the Mars Exploration Rover science team.

The bright white dot near the horizon to the right of center, labeled "Outcrop Promontory," (barely visible without labeling or zoom-in) is thought to be a light-toned outcrop on the far wall of the crater, suggesting that the rover can see over the low rim of Victoria. The northeast and southeast rims are labeled in bright green. Finally, the light purple lines and arrow highlight a small crater.

Image credit: NASA/JPL-Caltech/MSSS/Cornell University



This image from the Mars Orbiter Camera on NASA's Mars Global Surveyor highlights the Mars Exploration Rover Opportunity's approach toward "Victoria Crater."

North is to the left. Opportunity's location at sol 804 (April 29, 2006) is marked, as are the left and right edges of Victoria's rim from the rover's point of view. The labeled "promontory" is a bright spot that scientists believe is an outcrop on the far side of the crater. Marked in light purple is a small, 35-meter (115-foot) crater.

Victoria Crater is 800 meters (nearly half a mile) in diameter, about six times wider than "Endurance Crater," where Opportunity spent several months in 2004 examining rock layers affected by ancient water.

Image credit: NASA/JPL-Caltech/MSSS

Source: NASA/JPL - Mars Exploration Rovers - Opportunity

The grinding teeth have worn away on the rock abrasion tool of NASA's Mars Exploration Rover Spirit (after exposing interiors of five time more rock targets than its design goal of three rocks) but the tool still has useful wire bristles for brushing targets. In this image, a figure-eight-like imprint in the Martian soil marks the spot where Spirit has begun examining subsurface deposits layer by layer. The circular indentations resulted from brushing by the rock abrasion tool, one of several instruments on the rover's robotic arm. As an effective brushing tool it is now fulfilling a soil profiling experiment on a target called "Progress."

The experiment is a multi-step process of carefully brushing away fine layers of soil and then using the Mössbauer and alpha particle X-ray spectrometers, microscopic imager, and panoramic camera to examine the exposed surfaces during the long Martian winter.

This view is a mosaic of exposures taken by Spirit's microscopic imager during the rover's 830th Martian day (May 4, 2006). The total area shown is about 6 centimeters (2.4 inches) square.

Image credit: NASA/JPL/Cornell/USGS

Source: NASA/JPL - Mars Exploration Rovers - Spirit

As NASA's Mars Exploration Rover Opportunity continues to traverse from "Erebus Crater" toward "Victoria Crater," the rover navigates along exposures of bedrock between large, wind-blown ripples. Along the way, scientists have been studying fields of cobbles that sometimes appear on trough floors between ripples. They have also been studying the banding patterns seen in large ripples.

This view, obtained by Opportunity's panoramic camera on the rover's 802nd Martian day (sol) of exploration (April 27, 2006), is a mosaic spanning about 30 degrees. It shows a field of cobbles nestled among wind-driven ripples that are about 20 centimeters (8 inches) high.

The origin of cobble fields like this one is unknown. The cobbles may be a lag of coarser material left behind from one or more soil deposits whose finer particles have blown away. The cobbles may be eroded fragments of meteoritic material, secondary ejecta of Mars rock thrown here from craters elsewhere on the surface, weathering remnants of locally-derived bedrock, or a mixture of these. Scientists will use the panoramic camera's multiple filters to study the rock types, variability and origins of the cobbles.


Click on image for high resolution version.

This is an approximately true-color rendering that combines separate images taken through the panoramic camera's 753-nanometer, 535-nanometer and 432-nanometer filters.

Image credit: NASA/JPL-Caltech/Cornell


Cobbles in Troughs Between Meridiani Ripples (False Color)

Click on image for high resolution version.

This is a false-color rendering that combines separate images taken through the panoramic camera's 753-nanometer, 535-nanometer and 432-nanometer filters. The false color is used to enhance differences between types of materials in the rocks and soil.

Image credit: NASA/JPL-Caltech/Cornell

Source: NASA/JPL - Mars Exploration Rovers - Opportunity

It's a shame spirt and oppertunity r begining to show thier age.

It's hardly surprising that Spirit and Opportunity are showing signs of old age. Both have been operating for more than 820 sols (Martian days). They were designed to last for only 90 sols.

I didnt say I was suprized, I'm just saying its a shame. They lasted so long and did so much!

This composite of three images from the navigation camera shows the view from NASA's Mars Exploration Rover Opportunity toward the southeast, in the direction of "Victoria Crater," on the rover's 817th Martian day, or sol (May 12, 2006). To reach Victoria Crater, still about 1,100 meters (two-thirds of a mile) from this location, the rover must navigate among the large ripples visible on the left and ahead in the distance.

On this sol, Opportunity was preparing to deploy its arm instrument suite to analyze a rock on the outcrop pavement. At upper right is a small depression that was the target of further imaging on sols 825 and 826 (May 20 and 21, 2006).

Image credit: NASA/JPL-Caltech/Cornell

Source: NASA/JPL - Mars Exploration Rovers - Opportunity

Disturbed Soil Along the Path from 'Tyrone' (Close-Up)

Click on image for high resolution version.

This view shows tracks created by NASA's Mars Exploration Rover Spirit while traveling from the bright soil deposit seen in the upper right, informally named "Tyrone," to the vehicle's current location, dubbed "Winter Haven."

Spirit parked at "Winter Haven" on a small north-facing slope to maximize solar energy input during the Martian winter. This stayover presents an opportunity to do more intensive, long-term investigations of the rover's surroundings than are typically possible during warmer seasons when the vehicle spends more time driving from place to place. One of these activities is assessing the influence of wind by monitoring surface changes. Experience from the Viking Landers of the 1970s suggests that wind-related surface changes are more likely to occur in recently disturbed soil.

Shortly after arriving at Winter Haven, Spirit obtained this high-resolution view of disturbed soil for comparison with future images to help reveal any wind-related surface changes. The view is a mosaic of images of the rover's tracks, obtained through the 750-nanomater filter in the left eye of Spirit's panoramic camera on the rover's 835th Martian day, or sol (May 9, 2006).

Image credit: NASA/JPL-Caltech/Cornell


Disturbed Soil Along the Path from 'Tyrone'(Panorama)

Click on image for high resolution version.

This view shows tracks created by NASA's Mars Exploration Rover Spirit while traveling from the bright soil deposit seen in the upper right, informally named "Tyrone," to the vehicle's current location, dubbed "Winter Haven."

Spirit parked at "Winter Haven" on a small north-facing slope to maximize solar energy input during the Martian winter. This stayover presents an opportunity to do more intensive, long-term investigations of the rover's surroundings than are typically possible during warmer seasons when the vehicle spends more time driving from place to place. One of these activities is assessing the influence of wind by monitoring surface changes. Experience from the Viking Landers of the 1970s suggests that wind-related surface changes are more likely to occur in recently disturbed soil. This mosaic view combines two cameras' images of disturbed soil in Spirit's tracks, taken shortly after arriving at Winter Haven. It will provide a comparison with future images to help reveal any wind-related surface changes.

The mosaic includes images of the rover's tracks obtained through the left eye of the navigation camera on the rover's 807th Martian day, or sol (April 11, 2006), merged with higher-resolution images obtained through the 750-nanomater filter in the left eye of the panoramic camera on sol 835 (May 9, 2006).

Image credit: NASA/JPL-Caltech/Cornell



Source: NASA/JPL - Mars Exploration Rovers - Spirit

Click on image for high resolution version.

As NASA's Mars Exploration Rover Opportunity is traversing southward toward "Victoria Crater," it is periodically stopping to characterize exposed bedrock, using the contact instrument suite on the robotic arm. Between Martian days (sols) 818 and 821 of the mission (May 13 to May 16), one such characterization was carried out on a rock target called "Cheyenne." The target was brushed by the rock abrasion tool, analyzed by the alpha particle X-ray spectrometer and Mössbauer spectrometer, and photographed by the microscopic imager.

This image is a mosaic of four frames taken by the microscopic imager after the brush had removed dust and sand grains from most of the area shown, exposing the underlying bedrock. The resolution is 30 microns per pixel and the entire mosaic is 6 centimeters (2.4 inches) square. Opportunity acquired the images on Sol 819 (May 14, 2006) while the target was fully shadowed.

This rock surface exhibits relatively small spherical concretions compared to those observed in the vicinity of "Eagle Crater" and "Endurance Crater." Such small concretions, and in places apparent absence of concretions, have characterized the outcrops south of "Vostok Crater." Also visible in this image are small pits and grooves in the rock surface, including narrow, elongated void spaces different from any previously observed by Opportunity. Crystal-shaped and elongated void spaces that were seen in the vicinity of Eagle and Endurance Craters are interpreted as spaces left by dissolving of soluble salts. However, these features at Cheyenne have a significantly different appearance and the science team is considering a number of alternative hypotheses for their origin.

Image credit: NASA/JPL-Caltech/Cornell/USGS

Source: NASA/JPL - Mars Exploration Rovers - Opportunity

One part of the research program that NASA's Mars Exploration Rover Spirit is conducting while sitting at a favorable location for wintertime solar energy is the most detailed panorama yet taken on the surface of Mars. This view is a partial preliminary product from the continuing work on the full image, which will be called the "McMurdo Panorama."

Spirit's panoramic camera (Pancam) began taking exposures for the McMurdo Panorama on the rover's 814th Martian day (April 18, 2006). The rover has accumulated more than 900 exposures for this panorama so far, through all of the Pancam mineralogy filters and using little or no image compression. Even with a tilt toward the winter sun, the amount of energy available daily is small, so the job will still take one to two more months to complete.

This portion of the work in progress looks toward the north. "Husband Hill," which Spirit was climbing a year ago, is on the horizon near the center. "Home Plate" is a between that hill and the rover's current position. Wheel tracks imprinted when Spirit drove south from Home Plate can be seen crossing the middle distance of the image from the center to the right.

View Northward from Spirit's Winter Roost


Click on image for high resolution version.

This is an approximate true-color rendering combining exposures taken through three of the panoramic camera's filters. The filters used are centered on wavelengths of 750 nanometers, 530 nanometers and 430 nanometers.

Image credit: NASA/JPL/Cornell

View Northward from Spirit's Winter Roost (False Color)


Click on image for high resolution version.

This view is presented in false color to emphasize differences among rock and soil materials. It combines exposures taken through three of the panoramic camera's filters, centered on wavelengths of 750 nanometers, 530 nanometers and 430 nanometers.

Image credit: NASA/JPL/Cornell




The rock in the center foreground of this picture is suspected of being an iron meteorite. The panoramic camera on NASA's Mars Exploration Rover Spirit took this image during the rover's 809th Martian day (April 12, 2006). The foreground rock, informally named "Allan Hills," and a similar rock called "Zhong Shan," just out of the field of view to the left, have a smoother texture and lighter tone than other rocks in the area.

The texture and glossiness of this pair reminded some members of the rover science team of a rock called "Heat Shield Rock," which was observed by Opportunity, Spirit's twin, in the Meridiani region of Mars more than a year ago. Examination of that rock's composition confirmed it to be an iron meteorite (see http://photojournal.jpl.nasa.gov/catalog/PIA07269.)

Observations of Allan Hills and Zhong Shan with Spirit's miniature thermal emission spectrometer indicate that they are very reflective, like Heat Shield Rock. They are the first likely meteorites found by Spirit.

Rocks in the vicinity of Spirit's winter station are being assigned informal names honoring Antarctic research stations. Zhong Shan is an Antarctic base established by China in 1989. Allan Hills is a site where meteorites are frequently collected because they are relatively easy to see as dark rocks on the bright Antarctic ice. The most famous Allan Hills meteorite from Antarctica actually came from Mars and landed on Earth. If the Zhong Chang and Allan Hills rocks seen by Spirit do turn out to be iron-rich meteorites, they may have originated from an asteroid and landed on Mars



This view is an approximately true-color rendering that combines images taken through the panoramic camera's 753-nanometer, 535-nanometer, and 432-nanometer filters. It is a portion of an image previously released (see http://photojournal.jpl.nasa.gov/catalog/PIA08095).

Image Credit: NASA/JPL/Cornell



This view is an approximately true-color rendering that combines images taken through the panoramic camera's 753-nanometer, 535-nanometer, and 432-nanometer filters. It is a portion of an image previously released (see http://photojournal.jpl.nasa.gov/catalog/PIA08094).

Image Credit: NASA/JPL/Cornell

Source: NASA/JPL - Mars Exploration Rovers - Spirit

This animated piece illustrates the recent escape of NASA's Mars Exploration Rover Opportunity from dangerous, loose material on the vast plains leading to the rover's next long-term target, "Victoria Crater."

A series of images from the front and rear hazard-avoidance cameras make up this brief movie chronicling the challenge Opportunity faced to free itself from the ripple dubbed "Jammerbugt." Each quadrant shows one of the rover's four corner wheels: left front wheel in upper left, right front wheel in upper right, rear wheels in the lower quadrants. The wheels became partially embedded in the ripple at the end of a drive on Opportunity's 833rd Martian day, or sol (May 28, 2006). The images in this clip were taken on sols 836 through 841 (May 31 through June 5, 2006).

Scientists and engineers who had been elated at the meters of progress the rover had been making in earlier drives were happy for even centimeters of advance per sol as they maneuvered their explorer through the slippery material of Jammerbugt. The wheels reached solid footing on a rock outcrop on the final sol of this sequence.

The science and engineering teams appropriately chose the ripple's informal name from the name of a bay on the north coast of Denmark. Jammerbugt, or Jammerbugten, loosely translated, means Bay of Lamentation or Bay of Wailing. The shipping route from the North Sea to the Baltic passes Jammerbugt on its way around the northern tip of Jutland. This has always been an important trade route and many ships still pass by the bay. The prevailing wind directions are typically northwest to southwest with the strongest winds and storms tending to blow from the northwest. A northwesterly wind will blow straight into the Jammerbugt, towards shore. Therefore, in the age of sail, many ships sank there during storms. The shore is sandy, but can have strong waves, so running aground was very dangerous even though there are no rocks.

Fortunately, Opportunity weathered its "Jammerbugt" and is again on its way toward Victoria Crater.

Image credit: NASA/JPL-Caltech

Source: NASA/JPL - Mars Exploration Rovers - Opportunity

Click on image for high resolution version.

[font=Times New Roman]On its 825th Martian day (May 20, 2006), NASA's Mars Exploration Rover Opportunity stopped for the weekend to place its instrument arm onto the soil target pictured here, dubbed "Alamogordo Creek." Two views from the panoramic camera, acquired at about noon local solar time, are at the top. Below them is a close-up view from the microscopic imager.

At upper left, a false-color view emphasizes differences among materials in rocks and soil. It combines images taken through the panoramic camera's 753-nanometer, 535-nanometer and 432-nanometer filters. At upper right is an approximately true-color rendering made with the panoramic camera's 600-nanometer, 535-nanometer and 480-nanometer filters. The microscopic-imager frame covers the area outlined by the white boxes in the panoramic-camera views, a rectangle 3 centimeters (1.2 inches) across.

As Opportunity traverses to the south, it is analyzing soil and rocks along the way for differences from those seen earlier. At this site, the soil contains abundant small spherical fragments, thought to be hematite-rich concretions, plus finer-grained basaltic sand. Most of the spherical fragments seen in the microscopic image are smaller than those first seen at the rover's landing site in "Eagle Crater," some five kilometers (3.1 miles) to the north. However, a few larger spherical fragments and other rock fragments can also be seen in the panoramic-camera images.

Image credit: NASA/JPL/Cornell/USGS

Source: NASA/JPL - Mars Exploration Rovers - Opportunity

Stretching along "Low Ridge" in front of the winter haven for NASA's Mars Exploration Rover Spirit are several continuous rock layers that make up the ridge. Some of these layers form fins that stick out from the other rocks in a way that suggests that they are resistant to erosion. Spirit is currently straddling one of these fin-like layers and can reach a small bit of light-toned material that might be a broken bit of it. Informally named "Halley," this rock was broken by Spirit's wheels when the rover drove over it.

Spirit Examines Light-Toned 'Halley' (False Color)


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The first analyses of Halley showed it to be unusual in composition, containing a lot of the minor element zinc relative to the soil around it and having much of its iron tied up in the mineral hematite. When scientists again placed the scientific instruments on Spirit's robotic arm on a particularly bright-looking part of Halley, they found that the chemical composition of the bright spots was suggestive of a calcium sulfate mineral. Bright soils that Spirit has examined earlier in the mission contain iron sulfate.

This discovery raises new questions for the science team: Why is the sulfate mineralogy here different? Did Halley and the fin material form by water percolating through the layered rocks of Low Ridge? When did the chemical alteration of this rock occur? Spirit will continue to work on Halley and other light-toned materials along Low Ridge in the coming months to try to answer these questions.

Spirit took this red-green-blue composite image with the panoramic camera on the rover's 820th sol, or Martian day, of exploring Mars (April 24, 2006). The image is presented in false color to emphasize differences among materials in the rocks and soil. It combines frames taken through the camera's 750-nanometer, 530-nanometer, and 430-nanometer filters. The middle of the imaged area has dark basaltic sand. Spirit's wheel track is at the left edge of the frame. Just to the right of the wheel track in the lower left are two types of brighter material examined by Spirit at the Halley target. The bluer material yielded the evidence for a calcium sulfate mineral.

Image credit: NASA/JPL-Caltech/Cornell

Spirit Examines Light-Toned 'Halley' (Microscopic Image)


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Spirit's microscopic imager took this picture during the rover's 861st sol, or Martian day, of exploring Mars (June 5, 2006). The field of view is about 31 millimeters square (a square with sides of 1.2 inches). The light-toned soils in the bottom center and the top center of the image correspond to small, bright, bluish-white deposits just to the right of the rover's tracks in the lower left corner of an image from the panoramic camera [PIA08567].

The first analyses of Halley showed it to be unusual in composition, containing a lot of the minor element zinc relative to the soil around it and having much of its iron tied up in the mineral hematite. When scientists again placed the scientific instruments on Spirit's robotic arm on a particularly bright-looking part of Halley, they found that the chemical composition of the bright spots was suggestive of a calcium sulfate mineral. Bright soils that Spirit has examined earlier in the mission contain iron sulfate.

This discovery raises new questions for the science team: Why is the sulfate mineralogy here different? Did Halley and the fin material form by water percolating through the layered rocks of Low Ridge? When did the chemical alteration of this rock occur? Spirit will continue to work on Halley and other light-toned materials along Low Ridge in the coming months to try to answer these questions.

Image credit: NASA/JPL-Caltech/Cornell/USGS

Source: NASA/JPL - Mars Exploration Rovers - Spirit

(Unlabeled)

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(Labeled)

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This imagery from the panoramic camera on NASA's Mars Exploration Rover Opportunity shows the outcrop-rimmed "Beagle Crater" appearing on the horizon as Opportunity approaches it. The top version is vertically stretched to make horizon details easier to see. The lower version has normal proportions. The image is a mosaic of frames taken during Opportunity's 855th Martian day, or sol (June 20, 2006).

Beagle Crater is 35 meters (115 feet) in diameter. The Opportunity science and engineering teams hope to have the rover visit it on the way to "Victoria Crater." Beagle Crater was 310 meters (1,107 feet) away from Opportunity when this picture was taken. Even at this distance, blocks of ejecta can be seen around the prominent, raised rim of Beagle crater, suggesting that it may be among the youngest craters visited by Opportunity.

When scientists using orbital data calculated that they should be able to detect Victoria's rim in rover images, they scrutinized frames taken in the direction of the crater by the panoramic camera. To positively characterize the subtle horizon profile of the crater and some of the features leading up to it, researchers created this vertically-stretched image (top). The stretched image makes mild nearby dunes look like more threatening peaks, but that is only a result of the exaggerated vertical dimension. This vertical stretch technique was first applied to Viking Lander 2 panoramas by Philip Stooke, of the University of Western Ontario, Canada, to help locate the lander with respect to orbiter images. Vertically stretching the image allows features to be more readily identified by the Mars Exploration Rover science team. The bright white dot on the horizon near the upper left corner of the panorama, labeled "Outcrop Promontory," was thought to be a light-toned outcrop on the far wall of Victoria, based on a single azimuth measurement on sol 804 (April 28, 2006), suggesting that the rover was seeing over the low rim of Victoria. But comparing the azimuth angle of this feature in the sol 855 panorama and the angle of the same feature in the sol 804 panoramic image [PIA08446] (a process known as triangulation) revealed that this outcrop must instead be on the near rim of the crater.

The southeast rim of Victoria is labeled in bright green. The northeast rim is beyond the left edge of this panorama. The salmon-color lines and arrows highlight two small craters on the dark "annulus," or ring, around Victoria Crater.

Image credit: NASA/JPL-Caltech/MSSS/Cornell University

'Beagle Crater' on Opportunity's Horizon (Orbital View)


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This image from the Mars Orbiter Camera aboard NASA's Mars Global Surveyor highlights the Mars Exploration Rover Opportunity's approach toward "Beagle Crater."

North is to the left. Opportunity's locations at sols 804 (April 29, 2006) and 855 (June 20, 2006) are marked, as are the left and right edges of the rim of "Victoria Crater" from the rover's point of view. The labeled "promontory" is a bright spot that scientists originally thought was an outcrop on the far side of the crater, based on the single azimuth measurement on sol 804 [PIA08447]. But comparing the azimuth angle of this feature in the sol 855 panorama and the angle of the same feature in the sol 804 panoramic image (a process known as triangulation) revealed that this outcrop must instead be on the near rim of the crater. Marked in salmon are two small craters beyond Beagle crater that are on the dark "annulus," or ring, around Victoria Crater.

Victoria Crater is 730 meters to 750 meters (nearly half a mile) in diameter, about six times wider than "Endurance Crater," where Opportunity spent several months in 2004 examining rock layers affected by ancient water.

This image is an uncalibrated version that the rover team uses for planning. It has been reprojected and stretched in some places and isn't used for scientific purposes.

Image credit: NASA/JPL-Caltech/MSSS

Source: NASA/JPL - Mars Exploration Rovers - Opportunity

From its winter outpost at "Low Ridge" inside Gusev Crater, NASA's Mars Exploration Rover Spirit took this spectacular, color mosaic of hilly, sandy terrain and two potential iron meteorites. The two light-colored, smooth rocks about two-thirds of the way up from the bottom of the frame have been labeled "Zhong Shan" and "Allan Hills."

The two rocks' informal names are in keeping with the rover science team's campaign to nickname rocks and soils in the area after locations in Antarctica. Zhong Shang is an Antarctic base that the People's Republic of China opened on Feb. 26, 1989, at the Larsemann Hills in Prydz Bay in East Antarctica. Allan Hills is a location where researchers have found many Martian meteorites, including the controversial ALH84001, which achieved fame in 1996 when NASA scientists suggested that it might contain evidence for fossilized extraterrestrial life. Zhong Shan was the given name of Dr. Sun Yat-sen (1866-1925), known as the "Father of Modern China." Born to a peasant family in Guangdong, Sun moved to live with his brother in Honolulu at age 13 and later became a medical doctor. He led a series of uprisings against the Qing dynasty that began in 1894 and eventually succeeded in 1911. Sun served as the first provisional president when the Republic of China was founded in 1912.

The Zhong Shan and Allan Hills rocks, at the left and right, respectively, have unusual morphologies and miniature thermal emission spectrometer signatures that resemble those of a rock known as "Heat Shield" at the Meridiani site explored by Spirit's twin, Opportunity. Opportunity's analyses revealed Heat Shield to be an iron meteorite.

Possible Meteorites in the Martian Hills (False Color)

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Spirit acquired this false-color image on the rover's 872nd Martian day, or sol (June 16, 2006), using exposures taken through three of the panoramic camera's filters, centered on wavelengths of 750 nanometers, 530 nanometers, and 430 nanometers. The image is presented in false color to emphasize differences among materials in the rocks and soil.

Image credit: NASA/JPL-Caltech/Cornell

Possible Meteorites in the Martian Hills

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Spirit acquired this approximately true-color image on the rover's 872nd Martian day, or sol (June 16, 2006), using exposures taken through three of the panoramic camera's filters, centered on wavelengths of 600 nanometers, 530 nanometers, and 480 nanometers.

Image credit: NASA/JPL-Caltech/Cornell

Source: NASA/JPL - Mars Exploration Rovers - Spirit

Click on image for high resolution version.

The panoramic camera on NASA's Mars Exploration Rover Opportunity captured a sweeping image of "Burns Cliff" after driving right to the base of this southeastern portion of the inner wall of "Endurance Crater" in November 2004. This view is a color stereo anaglyph, offering a three-dimensionsal quality when seen properly through red/blue glasses. It incorporates imagery released previously (PIA07110). The image combines frames taken between the rover's 287th and 294th Martian days (Nov. 13 to 20, 2004). It spans about 180 degrees from side to side. Because of this wide-angle view, the cliff walls appear to bulge out toward the camera. In reality the walls form a gently curving, continuous surface.

Image credit: NSA/JPL/Cornell

Source: NASA/JPL - Mars Exploration Rovers - Opportunity

Engineers designed NASA's Mars Exploration Rovers to be exceptionally predictable when it comes to studying specific rocks and patches of soil. For example, each rover can remove the robotic arm from a target, switch scientific instruments, and resume analysis within 1 millimeter (0.04 inch) of the original position.

Most samples analyzed by the scientific instruments are large enough that a positioning accuracy of approximately 1 centimeter (0.4 inch) is acceptable. At the current winter outpost of NASA's Spirit rover, however, the science team was interested in analyzing a small, reflective spot only 1 centimeter (0.4 inch) in diameter associated with a rock target called "Halley". In this instance, a positioning error of 1 centimeter could have missed the target entirely. To be sure this wouldn't happen, team members created a 2x1 microscopic image mosaic of the target, shown here, based on stereo imaging models of the terrain obtained by Spirit on sol 861 (June 5, 2006). The stereo images from the hazard avoidance cameras provided detailed views as well as distance to features in the field of view. The region of interest - a bit of sparkly, light-toned material - turned out to be offset slightly.

Given the exceptional repeatability in positioning the robotic arm, engineers were able to transmit the desired coordinates for further study and direct the rover to place the alpha particle X-ray spectrometer and Mässbauer spectrometer in that particular spot, allowing analyses of the light-toned material. A subsequent microscopic image, 32 millimeters (1.2 inches) wide, of the target known as "Halley_Brunt," acquired on sol 880 (June 24, 2006), documented that the rover did, in fact, place both spectrometers in the optimum position and analyze the desired patch of sparkly material on the Martian surface.

Image credit: NASA/JPL-Caltech/Cornell/USGS

Source: NASA/JPL - Mars Exploration Rovers - Spirit

This approximately true-color rendering was generated from images obtained by NASA's Mars Exploration Rover Opportunity on sol 842 (June 7, 2006) using the panoramic camera's 600-nanometer, 530-nanometer, and 480-nanometer filters.


As winter has descended over Meridiani Planum, the availability of solar power for the rovers has diminished greatly. One consequence of less power for Opportunity is that there are fewer telecommunications links via the orbiting Mars Odyssey spacecraft because the rover needs to use the "deep sleep" mode overnight to conserve energy. As a result, images that are not needed specifically to help plan the next sol of operations often stay onboard for a much longer time than the science team has been used to. For example, on sol 833 Opportunity became embedded within an unexpectedly deep and very fine-grained ripple, named "Jammerbugt" by the operations team, and spent the next eight sols (834-841) extricating itself.

A series of images from the hazard avoidance camera were returned quickly because they were needed to help plan the drive sequences. However, once the rover was free from the ripple, the science team commanded these panoramic camera images on sol 842 to show complete coverage of the wheel tracks that were left by Opportunity during the extraction process. The images are of great scientific value but were not critical for planning operations. Accordingly, they were not fully downlinked until sol 864 (June 29, 2006), about three weeks after they were obtained.

Image credit: NASA/JPL-Caltech/Cornell

Source: NASA/JPL - Mars Exploration Rovers - Opportunity

During recent soil-brushing experiments, the rock abrasion tool on NASA's Mars Exploration Rover Spirit became covered with dust, as shown here. An abundance of iron oxide minerals in the dust gave the device a reddish-brown veneer. Investigators were using the rock abrasion tool to uncover successive layers of soil in an attempt to reveal near-surface stratigraphy. Afterward, remnant dirt clods were visible on both the bit and the brush of the tool. Designers of the rock abrasion tool at Honeybee Robotics and engineers at the Jet Propulsion Laboratory developed a plan to run the brush on the rock abrasion tool in reverse to dislodge the dirt and return the tool to normal operation. Subsequent communications with the rover revealed that the procedure is working and the rock abrasion tool remains healthy.

Spirit acquired this approximately true-color image with the panoramic camera on the rover's 893rd sol, or Martian day (July 8, 2006). The image combines exposures taken through three of the camera's filters, centered on wavelengths of 750 nanometers, 530 nanometers, and 430 nanometers.

Image credit: NASA/JPL-Caltech/Cornell

Source: NASA/JPL - Mars Exploration Rovers - Spirit

NASA's Mars Exploration Rover Opportunity acquired this false-color image of the rim of the 35-meter (115-foot) diameter Beagle Crater on Martian day, or sol, 894 (July 30, 2006) using the panoramic camera's 753-nanometer, 535-nanometer, and 432-nanometer filters. At the time the rover was about 25 meters (82 feet) from Beagle Crater, looking east-southeast. The image reveals ejecta blocks near the rover, the largest of which is about 50 centimeters (20 inches) across. The image also shows a portion of the eastern interior rim of Beagle Crater, which appears composed of jumbled, angular blocks of brighter and darker outcrop rocks. The rover will drive to the rim of Beagle and acquire an extensive color panorama of the crater rim and interior in the coming sols.

Image credit: NASA/JPL-Caltech/Cornell




NASA's Mars Exploration Rover Opportunity took this approximate true-color image of Beagle Crater from a distance of about 25 meters (82 feet). The crater is thought to be relatively young based on its prominent, raised rim and surrounding ejecta that have not been eroded away or buried by sand. The image also shows a portion of the eastern interior rim of Beagle Crater, which appears composed of jumbled, angular blocks of brighter and darker outcrop rocks. The rover will drive to the rim of the crater and acquire an extensive color panorama in the coming sols.

Image credit: NASA/JPL-Caltech/Cornell

Source: NASA/JPL - Mars Exploration Rovers - Opportunity

During the past two-and-a-half years of traversing the central part of Gusev Crater, NASA's Mars Exploration Rover Spirit has analyzed the brushed and ground-into surfaces of multiple rocks using the alpha particle X-ray spectrometer, which measures the abundance of major chemical elements. In the process, Spirit has documented the first example of a particular kind of volcanic region on Mars known as an alkaline igneous province. The word alkaline refers to the abundance of sodium and potassium, two major rock-forming elements from the alkali metals on the left-hand side of the periodic table.

All of the relatively unaltered rocks -- those least changed by wind, water, freezing, or other weathering agents -- examined by Spirit have been igneous, meaning that they crystallized from molten magmas. One way geologists classify igneous rocks is by looking at the amount of potassium and sodium relative to the amount of silica, the most abundant rock-forming mineral on Earth. In the case of volcanic rocks, the amount of silica present gives scientists clues to the kind of volcanism that occurred, while the amounts of potassium and sodium provide clues about the history of the rock. Rocks with more silica tend to erupt explosively. Higher contents of potassium and sodium, as seen in alkaline rocks like those at Gusev, may indicate partial melting of magma at higher pressure, that is, deeper in the Martian mantle. The abundance of potassium and sodium determines the kinds of minerals that make up igneous rocks. If igneous rocks have enough silica, potassium and sodium always bond with the silica to form certain minerals.

The Gusev rocks define a new chemical category not previously seen on Mars, as shown in this diagram plotting alkalis versus silica, compiled by University of Tennessee geologist Harry McSween. The abbreviations "Na2O" and "K2O" refer to oxides of sodium and potassium.