As part of its investigation of "Victoria Crater," NASA's Mars Exploration Rover Opportunity examined a section of the scalloped rim called "Bottomless Bay" (or "Bahia sin Fondo"). This view shows the northeastern side of Bottomless Bay as seen from the southwest. The exposures combined into this mosaic were taken by the rover's panoramic camera through a 750-nanometer filter during the 1,019th Martian day, or sol, of Opportunity's Mars-surface mission (Dec. 5, 2006).

Image Credit: NASA/JPL-Caltech/Cornell

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Source: NASA - Missions - MER

As part of its investigation of "Victoria Crater," NASA's Mars Exploration Rover Opportunity examined a section of the scalloped rim called "Bottomless Bay" (or "Bahia sin Fondo"). This view shows the northeastern side of Bottomless Bay as seen from the southwest. The exposures combined into this mosaic were taken by the rover's panoramic camera through a 750-nanometer filter during the 1,019th Martian day, or sol, of Opportunity's Mars-surface mission (Dec. 5, 2006). Contrast has been altered to improve the visibility of details in shadowed areas.

Image Credit: NASA/JPL-Caltech/Cornell

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Source: NASA - Missions - MER

As part of its investigation of "Victoria Crater," NASA's Mars Exploration Rover Opportunity examined a promontory called "Cape St. Mary" from the from the vantage point of "Cape Verde," the next promontory counterclockwise around the crater's deeply scalloped rim. This view of Cape St. Mary combines several exposures taken by the rover's panoramic camera into an approximately true-color mosaic.

The upper portion of the crater wall contains a jumble of material tossed outward by the impact that excavated the crater. This vertical cross-section through the blanket of ejected material surrounding the crater was exposed by erosion that expanded the crater outward from its original diameter, according to scientists' interpretation of the observations. Below the jumbled material in the upper part of the wall are layers that survive relatively intact from before the crater-causing impact. Near the base of the Cape St. Mary cliff are layers with a pattern called "crossbedding," intersecting with each other at angles, rather than parallel to each other. Large-scale crossbedding can result from material being deposited as wind-blown dunes.

The images combined into this mosaic were taken during the 970th Martian day, or sol, of Opportunity's Mars-surface mission (Oct. 16, 2006). The panoramic camera took them through the camera's 750-nanometer, 530-nanometer and 430-nanometer filters.

Image Credit: NASA/JPL-Caltech/Cornell

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Source: NASA - Missions - MER

As part of its investigation of "Victoria Crater," NASA's Mars Exploration Rover Opportunity examined a promontory called "Cape St. Mary" from the from the vantage point of "Cape Verde," the next promontory counterclockwise around the crater's deeply scalloped rim. This view of Cape St. Mary combines several exposures taken by the rover's panoramic camera into an approximately true-color mosaic with contrast adjusted to improve the visibility of details in shaded areas.

The upper portion of the crater wall contains a jumble of material tossed outward by the impact that excavated the crater. This vertical cross-section through the blanket of ejected material surrounding the crater was exposed by erosion that expanded the crater outward from its original diameter, according to scientists' interpretation of the observations. Below the jumbled material in the upper part of the wall are layers that survive relatively intact from before the crater-causing impact. Near the base of the Cape St. Mary cliff are layers with a pattern called "crossbedding," intersecting with each other at angles, rather than parallel to each other. Large-scale crossbedding can result from material being deposited as wind-blown dunes.

The images combined into this mosaic were taken during the 970th Martian day, or sol, of Opportunity's Mars-surface mission (Oct. 16, 2006). The panoramic camera took them through the camera's 750-nanometer, 530-nanometer and 430-nanometer filters.

Image Credit: NASA/JPL-Caltech/Cornell

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Source: NASA - Missions - MER

As part of its investigation of "Victoria Crater," NASA's Mars Exploration Rover Opportunity examined a promontory called "Cape St. Mary" from the from the vantage point of "Cape Verde," the next promontory counterclockwise around the crater's deeply scalloped rim. This view of Cape St. Mary combines several exposures taken by the rover's panoramic camera into a false-color mosaic. Contrast has been adjusted to improve the visibility of details in shaded areas.

The upper portion of the crater wall contains a jumble of material tossed outward by the impact that excavated the crater. This vertical cross-section through the blanket of ejected material surrounding the crater was exposed by erosion that expanded the crater outward from its original diameter, according to scientists' interpretation of the observations. Below the jumbled material in the upper part of the wall are layers that survive relatively intact from before the crater-causing impact. Near the base of the Cape St. Mary cliff are layers with a pattern called "crossbedding," intersecting with each other at angles, rather than parallel to each other. Large-scale crossbedding can result from material being deposited as wind-blown dunes.

The images combined into this mosaic were taken during the 970th Martian day, or sol, of Opportunity's Mars-surface mission (Oct. 16, 2006). The panoramic camera took them through the camera's 750-nanometer, 530-nanometer and 430-nanometer filters. The false color enhances subtle color differences among materials in the rocks and soils of the scene.

Image Credit: NASA/JPL-Caltech/Cornell

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Source: NASA - Missions - MER

As part of its investigation of "Victoria Crater," NASA's Mars Exploration Rover Opportunity examined a promontory called "Cape Verde" from the vantage point of "Cape St. Mary," the next promontory clockwise around the crater's deeply scalloped rim. This view of Cape Verde combines several exposures taken by the rover's panoramic camera into an approximately true-color mosaic. The exposures were taken during late-morning lighting conditions.

The upper portion of the crater wall contains a jumble of material tossed outward by the impact that excavated the crater. This vertical cross-section through the blanket of ejected material surrounding the crater was exposed by erosion that expanded the crater outward from its original diameter, according to scientists' interpretation of the observations. Below the jumbled material in the upper part of the wall are layers that survive relatively intact from before the crater-causing impact.

The images combined into this mosaic were taken during the 1,006th Martian day, or sol, of Opportunity's Mars-surface mission (Nov. 22, 2006). The panoramic camera took them through the camera's 750-nanometer, 530-nanometer and 430-nanometer filters.

Image Credit: NASA/JPL-Caltech/Cornell

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Source: NASA - Missions - MER

As part of its investigation of "Victoria Crater," NASA's Mars Exploration Rover Opportunity examined a promontory called "Cape Verde" from the vantage point of "Cape St. Mary," the next promontory clockwise around the crater's deeply scalloped rim. This view of Cape Verde combines several exposures taken by the rover's panoramic camera into a false-color mosaic. The exposures were taken during late-morning lighting conditions.

The upper portion of the crater wall contains a jumble of material tossed outward by the impact that excavated the crater. This vertical cross-section through the blanket of ejected material surrounding the crater was exposed by erosion that expanded the crater outward from its original diameter, according to scientists' interpretation of the observations. Below the jumbled material in the upper part of the wall are layers that survive relatively intact from before the crater-causing impact.

The images combined into this mosaic were taken during the 1,006th Martian day, or sol, of Opportunity's Mars-surface mission (Nov. 22, 2006). The panoramic camera took them through the camera's 750-nanometer, 530-nanometer and 430-nanometer filters. The false color enhances subtle color differences among materials in the rocks and soils of the scene.

Image Credit: NASA/JPL-Caltech/Cornell

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Source: NASA - Missions - MER

As part of its investigation of "Victoria Crater," NASA's Mars Exploration Rover Opportunity examined a promontory called "Cape Verde" from the vantage point of "Cape St. Mary," the next promontory clockwise around the crater's deeply scalloped rim. This view of Cape Verde combines several exposures taken by the rover's panoramic camera into an approximately true-color mosaic. The exposures were taken during mid-afternoon lighting conditions.

The upper portion of the crater wall contains a jumble of material tossed outward by the impact that excavated the crater. This vertical cross-section through the blanket of ejected material surrounding the crater was exposed by erosion that expanded the crater outward from its original diameter, according to scientists' interpretation of the observations. Below the jumbled material in the upper part of the wall are layers that survive relatively intact from before the crater-causing impact.

The images combined into this mosaic were taken during the 1,006th Martian day, or sol, of Opportunity's Mars-surface mission (Nov. 22, 2006). The panoramic camera took them through the camera's 750-nanometer, 530-nanometer and 430-nanometer filters.

Image Credit: NASA/JPL-Caltech/Cornell

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Source: NASA - Missions - MER

As part of its investigation of "Victoria Crater," NASA's Mars Exploration Rover Opportunity examined a promontory called "Cape Verde" from the vantage point of "Cape St. Mary," the next promontory clockwise around the crater's deeply scalloped rim. This view of Cape Verde combines several exposures taken by the rover's panoramic camera into a false-color mosaic. The exposures were taken during mid-afternoon lighting conditions.

The upper portion of the crater wall contains a jumble of material tossed outward by the impact that excavated the crater. This vertical cross-section through the blanket of ejected material surrounding the crater was exposed by erosion that expanded the crater outward from its original diameter, according to scientists' interpretation of the observations. Below the jumbled material in the upper part of the wall are layers that survive relatively intact from before the crater-causing impact.

The images combined into this mosaic were taken during the 1,006th Martian day, or sol, of Opportunity's Mars-surface mission (Nov. 22, 2006). The panoramic camera took them through the camera's 750-nanometer, 530-nanometer and 430-nanometer filters. The false color enhances subtle color differences among materials in the rocks and soils of the scene.

Image Credit: NASA/JPL-Caltech/Cornell

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Source: NASA - Missions - MER

This is a portion of an image called the "McMurdo Panorama," taken by the panoramic camera on NASA's Spirit rover during its winter campaign of 2006. The view is looking toward the north at "Husband Hill," the dark-toned "El Dorado" dune field and the light-toned "Home Plate" feature. Husband Hill is approximately 850 meters (2,800 feet) from the rover's winter campaign site. Wind-blown ripples are evident in the field in the foreground, along with vesicular basalt rock. Tracks made by Spirit as it left Home Plate are also visible.

The McMurdo Panorama (link to http://photojournal.jpl.nasa.gov/catalog/PIA01907) was acquired over several months while Spirit was on "Low Ridge." It required all of the camera's geology filters and covered 360 degrees in azimuth. This view is in false color, with blue, green and red representing data collected through 430-nanometer, 530-nanometer and 750-nanometer filters, respectively.

Image credit: NASA/JPL-Caltech/Cornell

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Source: NASA - Missions - MER

This is a portion of an image, called the "McMurdo Panorama," taken by the panoramic camera on the Spirit rover during its winter campaign. The view is looking toward the east, at "Tyrone," the light-toned soils exposed by the rover's wheels. The Tyrone area proved difficult for Spirit to get through, so the rover was commanded to traverse to "Low Ridge," the site of the winter campaign. Note the light-toned material in the wheel tracks generated as the rover drove to the site. Several rock and soil targets are shown that were investigated with instruments on the rover's robotic arm

The McMurdo Panorama (link to http://photojournal.jpl.nasa.gov/catalog/PIA01907) was acquired over several months while Spirit was on "Low Ridge." It required all of the camera's geology filters and covered 360 degrees in azimuth. This view is in false color, with blue, green and red representing data collected through 430-nanometer, 530-nanometer and 750-nanometer filters, respectively.

Image credit: NASA/JPL-Caltech/Cornell
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Source: NASA - Missions - MER

This mosaic was made from frames acquired by the microscopic imager on NASA's Mars Exploration Rover Spirit during Spirit's 1,031 Martian day, or sol, on the red planet (Nov. 27, 2006). It shows a rock target called "King George Island" after the target was brushed by the rover's rock abrasion tool. The mosaic covers approximately 6 centimeters (2.4 inches) across and shows the granular nature of the rock exposure. The grains are typically about 1 millimeter (.04 inches) wide. Data from the rover's Moessbauer spectrometer provides evidence that they have an enhanced amount of the mineral hematite relative to surrounding soils.

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

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Source: NASA - Missions - MER

This perspective view looking toward the northeast shows part of the Columbia Hills range inside Gusev Crater. At the center is the winter campaign site of NASA's Mars Exploration Rover Spirit.

On its 805th Martian day, or sol, (April 8, 2006), Spirit was parked on a slope tilting 11 degrees to the north to maximize sunlight on the solar panels during the southern winter season. Science observations were formulated to take advantage of the long time during which the rover was parked. The plan focused on two tasks: tracking atmospheric and surface dynamics by periodically surveying the surface and atmosphere; and extensively examining surrounding terrains, rocks and soils using the panoramic camera and the miniature thermal emission spectrometer, coupled with long duration measurements using the alpha particle X-ray and Moessbauer spectrometers of rock and soil targets. For reference, the feature known as "Home Plate" is approximately 90 meters (295 feet) wide.

An image from Mars Global Surveyor's Mars Orbital Camera, catalogued as E03_00012 and courtesy Malin Space Science Systems, was used as the base image for this figure. The perspective was generated using elevation data generated from analyses of the camera's stereo images by the U.S. Geological Survey, Flagstaff, Ariz.

Image Credit: NASA/JPL-Caltech/MSSS/USGS

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NASA's twin Mars rovers, nearing the third anniversary of their landings, are getting smarter as they get older.

The unexpected longevity of Spirit and Opportunity is giving the space agency a chance to field-test on Mars some new capabilities useful both to these missions and future rovers. Spirit will begin its fourth year on Mars on Jan. 3 (PST); Opportunity on Jan. 24. In addition to their continuing scientific observations, they are now testing four new skills included in revised flight software uploaded to their onboard computers.


Image above: Rover Spirit as viewed by
NASA's Mars Reconnaissance Orbiter. The
orbiter's high-resolution camera took this
picture on Sept. 29, 2006.
+ Browse version of image

One of the new capabilities enables spacecraft to examine images and recognize certain types of features. It is based on software developed for NASA's Space Technology 6 "thinking spacecraft."

Spirit has photographed dozens of dusty whirlwinds in action, and both rovers have photographed clouds. Until now, however, scientists on Earth have had to sift through many transmitted images from Mars to find those few. With the new intelligence boost, the rovers can recognize dust devils or clouds and select only the relevant parts of those images to send back to Earth. This increased efficiency will free up more communication time for additional scientific investigations.

To recognize dust devils, the new software looks for changes from one image to the next, taken a few seconds apart, of the same field of view. To find clouds, it looks for non-uniform features in the portion of an image it recognizes as the sky.

Another new feature, called "visual target tracking," enables a rover to keep recognizing a designated landscape feature as the rover moves. Khaled Ali of NASA's Jet Propulsion Laboratory, Pasadena, Calif., flight software team leader for Spirit and Opportunity, said, "The rover keeps updating its template of what the feature looks like. It may be a rock that looks bigger as the rover approaches it, or maybe the shape looks different from a different angle, but the rover still knows it's the same rock."

Visual target tracking can be combined with a third new feature -- autonomy in calculating where it is safe to reach out with the contact tools on the rover's robotic arm. The combination gives Spirit and Opportunity a capability called "go and touch," which is yet to be tested on Mars. So far in the mission, whenever a rover has driven to a new location, the crew on Earth has had to evaluate images of the new location to decide where the rover could place its contact instruments on a subsequent day. After the new software has been tested and validated, the crew will have the option of letting a rover choose an arm target for itself the same day it drives to a new location.

The new software also improves the autonomy of each rover for navigating away from hazards by building better maps of their surroundings than they have done previously. This new capability was developed by Carnegie Mellon University, Pittsburgh, and JPL.

"Before this, the rovers could only think one step ahead about getting around an obstacle," said JPL's Dr. John Callas, project manager for the Mars Exploration Rovers. "If they encountered an obstacle or hazard, they'd back off one step and try a different direction, and if that direction didn't work they'd try another, then another. And sometimes the rover could not find a solution. With this new capability, the rover will be smarter about navigating in complex terrain, thinking several steps ahead. It could back out of a dead-end cul-de-sac. It could even find its way through a maze."

This is the most comprehensive of four revisions to the rovers' flight software since launch. One new version was uplinked during the cruise to Mars, and the rovers have switched to upgraded versions twice since their January 2004 landings.

Callas said, "These rovers are a great resource for testing software that could be useful to future Mars missions without sacrificing our own continuing mission of exploration. This new software will be a baseline for development of flight software for Mars Science Laboratory, but it's also helpful in operating Spirit and Opportunity." NASA's Mars Science Laboratory is a next-generation Mars rover in development for planned launch in 2009.

Spirit and Opportunity have worked on Mars for nearly 12 times as long as their originally planned prime missions of 90 Martian days. Spirit has driven about 6.9 kilometers (4.3 miles); Opportunity has driven about 9.8 kilometers (6.1 miles). Spirit has returned more than 88,500 images, Opportunity more than 80,700. All the raw images are available online at http://marsrovers.jpl.nasa.gov/gallery/all/.

Currently, Spirit is investigating rocks and soils near a ridge where it kept its solar panels tilted toward the sun during the Martian winter. Opportunity is exploring "Victoria Crater," where cliffs in the crater wall expose rock layers with clues about a larger span of Mars history than the rover has previously examined.

Opportunity's key discovery since landing has been mineral and rock-texture evidence that water drenched and flowed over the surface in at least one region of Mars long ago. Spirit has found evidence that water in some form has altered mineral composition of some soils and rocks in older hills above the plain where the rover landed.

Among the rovers' many other accomplishments:

-- Opportunity has analyzed a series of exposed rock layers recording changing environmental conditions from the times when the layers were deposited and later modified. Wind-blown dunes came and went. The water table fluctuated.

-- Spirit has recorded dust devils forming and moving, events which were made into movie clips. These provide new insight into the interaction of Mars' atmosphere and surface.

-- Both rovers have found metallic meteorites on Mars. Opportunity found one rock with a composition similar to a meteorite that reached Earth from Mars.

NASA's Mars Technology Program and New Millennium Program sponsored development of the new capabilities included in the new flight software.

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, visit http://www.nasa.gov/rovers. For descriptions of technologies being developed for future Mars missions, see http://marstech.jpl.nasa.gov. For information about the New Millennium Program's Space Technology 6 mission, see http://nmp.nasa.gov/st6/.

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

2006-152

Source: NASA/JPL - News

NASA's Mars Exploration Rover Opportunity captured this vista of "Victoria Crater" from the viewpoint of "Cape Verde," one of the promontories that are part of the scalloped rim of the crater. Opportunity drove onto Cape Verde shortly after arriving at the rim of Victoria in September 2006. The view combines hundreds of exposures taken by the rover's panoramic camera (Pancam). The camera began taking the component images during Opportunity's 970th Martian day, or sol, on Mars (Oct. 16, 2006). Work on the panorama continued through the solar conjunction period, when Mars was nearly behind the sun from Earth's perspective and communications were minimized. Acquisition of images for this panorama was completed on Opportunity's 991st sol (Nov. 7, 2006).

The top of Cape Verde is in the immediate foreground at the center of the image. To the left and right are two of the more gradually sloped bays that alternate with the cliff-faced capes or promontories around the rim of the crater. "Duck Bay," where Opportunity first reached the rim, is to the right. Beyond Duck Bay counterclockwise around the rim, the next promontory is "Cabo Frio," about 150 meters (500 feet) from the rover. On the left side of the panorama is "Cape St. Mary," the next promontory clockwise from Cape Verde and about 40 meters (130 feet) from the rover. The vantage point atop Cape Verde offered a good view of the rock layers in the cliff face of Cape St. Mary, which is about 15 meters or 50 feet tall. By about two weeks after the Pancam finished collecting the images for this panorama, Opportunity had driven to Cape St. Mary and was photographing Cape Verde's rock layers.

The far side of the crater lies about 800 meters (half a mile) away, toward the southeast.

This approximately true-color view combines images taken through three of the Pancam's filters, admitting light with wavelengths centered at 750 nanometers (near infrared), 530 nanometers (green) and 430 nanometers (violet).

Image credit: NASA/JPL-Caltech/Cornell

Panorama from 'Cape Verde' (False Color)


Click on image for high resolution version.

This view combines images taken through three of the Pancam's filters, admitting light with wavelengths centered at 750 nanometers (near infrared), 530 nanometers (green) and 430 nanometers (violet). It is presented in false color to emphasize differences among materials in the rocks and soils.

Image credit: NNASA/JPL-Caltech/Cornell

Source: NASA/JPL - Mars Exploration Rovers - Opportunity

Rovers Get New Driving Capability (Animation)

Until recently, NASA's two Mars rovers, Spirit and Opportunity, could figure only one or two steps ahead in planning a path and driving on their own. New software uploaded to the rovers onboard computers now enables them to look ahead and plan a path to a spot 50 meters (164 feet) away, evading obstacles along the way. With this software, called "Field D-Star" path planner and developed at Carnegie Mellon University, Pittsburgh, the rovers could find their way out of a maze.

Opportunity ran the first test of its smarter autonomous driving capability on the rover's 1,014th sol, or Martian day (Nov. 30, 2006). This animation uses color codings to depict that drive. Red areas are "keep-out" zones established by human rover drivers to prevent Opportunity from getting too close to the edge of "Victoria Crater." White represents unknown areas. Green represents areas that would be safe to traverse based on stereo images taken by the rover's navigation cameras. The moving purple diamond represents Opportunity itself. The blue line is the most efficient path to the desired destination. During this particular 10.5-meter (34-foot) drive, Opportunity's new software was still only a backseat driver, watching what happened and making plans but letting the rest of the system handle the driving. The rover still relied on the one-step-ahead system it had been using before getting the new software. Future tests will put the software directly in the driver's seat. So far, tests have been successful.

Image credit: NASA/JPL-Caltech/CMU

Rovers Get New Driving Capability (Site of Test)

Opportunity ran the first test of its smarter autonomous driving capability on the rover's 1,014th sol, or Martian day (Nov. 30, 2006). This overhead view shows the site of the test. The rover's software path (inside the blue box) is superimposed upon an image taken by NASA's Mars Reconnaissance Orbiter, a portion of image PIA08813. Around the rover are the sands of Meridiani Planum; "Victoria Crater" is on the right. Red areas are "keep-out" zones established by human rover drivers to prevent Opportunity from getting too close to the edge of the crater. Green represents areas that would be safe to traverse based on stereo images taken by the rover's navigation cameras. The purple diamond represents Opportunity and the blue diamond the destination. The blue line is the most efficient path to the desired destination.

Image credit: NASA/JPL-Caltech/Univ. of Arizona/CMU

Source: NASA/JPL - Mars Exploration Rovers - Opportunity

NASA's Mars Exploration Rover Opportunity captured a view of wispy afternoon clouds, not unlike fair weather clouds on Earth, passing overhead on the rover's 956th sol, or Martian day (Oct. 2, 2006). With Opportunity facing northeast, the clouds appear to drift gently toward the west in this movie taken with the rover's navigation camera.

The 10 frames, taken 32 seconds apart, show the formation and evolution of what are likely mid-level, convective water clouds. Such clouds are common near Mars' equator at this time of the Martian year. They have been observed by both of NASA's Mars Exploration Rovers, by satellites orbiting Mars, and by the Hubble Space Telescope. In this case, the clouds appear to develop at a fixed location, in the center of the frame about 25 degrees above the horizon. This style of origin suggests that a thermal plume is rising over a surface feature. In spite of apparent winds aloft, the thermal plume appears to remain stationary for the 5-minute duration of the movie.

Though scientists have determined from the images that the wind bearing is east-northeast, approximately 80 degrees, it is not possible on the basis of the movie to unambiguously determine the height and speed of the clouds. Scientists estimate, based on models of atmospheric wind profiles and the apparent displacement of the clouds, that all of the clouds in the movie are at about the same height somewhere between 5 kilometers and 25 kilometers (3 to 20 miles) above the surface. The clouds are estimated to be moving at 2.5 meters per second, if they are low, to 12.5 meters per second, if they are high (8 feet per second to 41 feet per second).

Like clouds on Earth, these Martian clouds are probably composed of ice crystals and possibly supercooled water droplets. They are similar in appearance to terrestrial cirrocumulus or high altocumulus clouds. On Earth, such clouds are relatively transient and consist of small, individual cloudlets arranged in rippled patterns. They usually form 6 kilometers to 12 kilometers (4 to 7 miles) above Earth's surface by a process known as convection, during which warm air rises and cools, with clouds condensing from the moist air once it has cooled sufficiently.

These Martian clouds appear to be associated with a broader layer of ice-crystal clouds fanning out toward the upper right of the frames at the end of the movie. This is similar to the occurrence of terrestrial cirrocumulus and altocumulus clouds within layers of cirrus or cirrostratus clouds on Earth. Also apparent in this movie are prominent waves in the clouds, a result of the effect of gravity waves on cloud thickness, as on Earth.

Though both rovers now have the ability to autonomously detect clouds, these images were taken prior to the first use of the new abilities. The images shown here were stored on Opportunity and were transmitted to Earth on sol 1056 (Jan. 12, 2007) during a routine communications pass.

Image credit: NASA/JPL/Texas A&M/Cornell

Source: NASA/JPL - Mars Exploration Rovers - Opportunity

Looks like Earth...Mars was once an Earth. Just give NASA time to prove it. It will take a manned flight, but there are, in my opinion, many things to be found and told.

What if you saw your shadow on Mars and it wasn't human? Then you might be the Mars Exploration Rover Opportunity currently roaming the red planet. Opportunity and sister robot Spirit have been probing Mars since early 2004, finding evidence of ancient water, and sending breathtaking images across the inner solar system. Pictured above, Opportunity looks opposite the sun into Endurance Crater and sees its own shadow. Two of its wheels are visible, while the floor and walls of the unusual crater are visible in the background. Opportunity and Spirit have now spent over three years exploring the red planet, finding new clues into the wet ancient past of our solar system's second most habitable planet.

Image credit: NASA/JPL

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Source: NASA - Multimedia - Image of the Day Gallery

Since April of 2006, NASA's Mars Exploration Rover Spirit has been sojourning in a place called "Winter Haven," where the robotic geologist spent several months parked on a north-facing slope in order to keep its solar panels pointed toward the sun. During that time, while the rover spent the daylight hours conducting as much scientific research as possible, science team members assigned informal names to rock outcrops, boulders, and patches of soil commemorating exploration sites in Antarctica and the southernmost islands of South America. Antarctic bases are places where researchers, like the rovers on Mars, hunker down for the winter in subzero temperatures. During the past Martian winter, Spirit endured temperatures lower than minus 100 degrees Celsius (minus 148 degrees Fahrenheit).

This full-color mosaic of images acquired by the rover's panoramic camera shows the various features of the landscape near Spirit's "Winter Haven" and the informal names used to identify them. With Martian spring just around the corner and solar power levels on the rise, Spirit has been driving again. Scientists hope to return to the circular, plateau-like feature known as "Home Plate," though it will take some weeks to get there with a dragging right front wheel after visiting other points of scientific interest along the way. An unlabeled version of this panorama is online at http://photojournal.jpl.nasa.gov/catalog/PIA01907.

Image credit: NASA/JPL-Caltech/Cornell

Source: NASA/JPL - Mars Exploration Rovers - Spirit

NASA's Mars Exploration Rover Opportunity extended its cumulative Martian driving record to more than 10 kilometers (6.2 miles) by crossing 50.51 meters (165.7 feet) of flat ground during the 1,080th Martian day since arriving on Mars. This view shows the surroundings at the completion of the day's drive. It is a mosaic of frames taken by Opportunity's navigation camera.

The drive continued Opportunity's clockwise progress around the rim of "Victoria Crater," which is visible near the horizon. Opportunity began its fourth year of exploring Mars in January 2007. Its mission was originally planned for three months, with a driving-distance goal of 600 meters (1,969 feet).
Image credit: NASA/JPL-Caltec

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Source: NASA - Missions - MER

Some bright Martian soil containing lots of sulfur and a trace of water intrigues researchers who are studying information provided by NASA's Spirit rover.

"This material could have been left behind by water that dissolved these minerals underground, then came to the surface and evaporated, or it could be a volcanic deposit formed around ancient gas vents," said Dr. Ray Arvidson of Washington University, St. Louis. He is the deputy principal investigator for NASA's twin Mars rovers, Spirit and Opportunity.

Determining which of those two hypotheses is correct would strengthen understanding of the environmental history of the Columbia Hills region that Spirit has been exploring since a few months after landing on Mars in January 2004. However, investigating the bright soil presents a challenge for the rover team, because the loose material could entrap the rover.

Image above: 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, taken on the rover's 788th Martian day, or sol, of exploration (March 22, 2006), shows the strikingly bright tone and large extent of the materials uncovered. Image credit: NASA/JPL-Caltech/Cornell
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The bright white and yellow material was hidden under a layer of normal-looking soil until Spirit's wheels churned it up while the rover was struggling to cross a patch of unexpectedly soft soil nearly a year ago. The right front wheel had stopped working a week earlier. Controllers at NASA's Jet Propulsion Laboratory, Pasadena, Calif., were trying to maneuver the rover backwards, dragging that wheel, to the north slope of a hill in order to spend the southern-hemisphere winter with solar panels tilted toward the sun.

Due to the difficulty crossing that patch, informally named "Tyrone," the team chose to drive Spirit to a smaller but more accessible slope for the winter. Spirit stayed put in its winter haven for nearly seven months. Tyrone was one of several targets Spirit examined from a distance during that period, using an infrared spectrometer to check their composition. The instrument detected small amounts of water bound to minerals in the soil.

The rover resumed driving in late 2006 when the Martian season brought sufficient daily sunshine to the solar panels. Some of the bright soil from Tyrone was dragged to the winter site by the right front wheel, and Spirit spent some time measuring the composition and mineralogy of these materials. The material is sulfur-rich and consists of sulfate salts associated with iron, and likely calcium. "These salts could have been concentrated by hydrothermal liquid or vapor moving through the local rocks," said rover science team member Dr. Albert Yen, a geochemist at JPL. Two other patches of bright soil uncovered by Spirit before Tyrone were also sulfur-rich, but each had similarities to local rock compositions that were different at the three sites, suggesting localized origins.

Researchers will watch for more patches of bright soil. "If we find them along fractures, that would suggest they were deposited at ancient gas vents," Arvidson said. "If they are at the saddles between hills, that would suggest the deposits formed where groundwater came to the surface."

Scientists are describing recent findings by Spirit and Opportunity at the Lunar and Planetary Science Conference this week in League City, Texas.

Spirit has driven away from the Tyrone area for a clockwise circuit around a plateau called "Home Plate." Researchers want to learn more about Home Plate, which Spirit visited briefly in early 2006. They are checking a hypothesis that explosive volcanism, driven by the interaction of magma with water, formed Home Plate and similar features.

Halfway around Mars, Opportunity is exploring clockwise around "Victoria Crater," a bowl about 800 meters (half a mile) across. Cliff-like promontories alternate with more gradually sloped alcoves around the scalloped rim. The impact that dug the crater exposed layers that had been buried.

"The images are breathtaking," said Dr. Steve Squyres of Cornell University, principal investigator for the rovers. "Every promontory we've seen has the kinds of layering expected for ancient wind-blown sand deposits."

The layers consist of sulfate-rich sandstone similar to other bedrock Opportunity has been finding in Mars' Meridiani region for more than three years. The minerals come from a wet period in the region's ancient past. While exploring Victoria's rim with Opportunity, researchers have been on the lookout for rocks that might have been tossed out from layers deeper and older than the sulfates.

"We found one group of cobbles that were clearly more resistant to erosion than the sulfate blocks thrown out onto the rim," Squyres said. "We checked the composition of one that we called Santa Catarina. Our suspicion now is that Santa Catarina is a piece of a meteorite." That would be the fifth meteorite found by the rovers.

More than three years into what was planned as a three-month mission on Mars, both Spirit and Opportunity remain in good health, though with signs of aging. "The team has learned how to drive Spirit very well with just five wheels," said JPL's Dr. John Callas, rover project manager. "We could accomplish longer drives if there were more energy, but Spirit's solar panels have gotten really dusty. We would welcome another wind-related cleaning event." It's about the same time of year on Mars now as it was when winds blew dust off Spirit and its solar panels in 2005, increasing energy output.

JPL, a division of the California Institute of Technology, Pasadena, manages the Mars Exploration Rover project for NASA's Science Mission Directorate. For images and information about the rovers, visit http://www.nasa.gov/rovers.


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

2007-029

Source: NASA - Missions - Mars Rovers

On sol 1120 (February 26, 2007), the navigation camera aboard NASA's Mars Exploration Rover Spirit captured one of the best dust devils it's seen in its three-plus year mission. The series of navigation camera images were put together to make a dust devil movie.

The dust devil column is clearly defined and is clearly bent in the down wind direction. Near the end of the movie, the base of the dust devil becomes much wider. The atmospheric science team thinks that this is because the dust devil encountered some sand and therefore produced a "saltation skirt," an apron of material that is thrown out of the dust devil because it is too large to be carried up into suspension.

Also near the end of the movie the dust devil seems to move faster across the surface. This is because Spirit began taking pictures less frequently, and not because the dust devil sped up.

Image credit: NASA/JPL-Caltech



On sol 1149 (March 28, 2007) of its mission, NASA's Mars Exploration Rover Spirit caught a wind gust with its navigation camera. A series of navigation camera images were strung together to create this movie. The front of the gust is observable because it was strong enough to lift up dust. From assessing the trajectory of this gust, the atmospheric science team concludes that it is possible that it passed over the rover. There was, however, no noticeable increase in power associated with this gust. In the past, dust devils and gusts have wiped the solar panels of dust, making it easier for the solar panels to absorb sunlight.

Image credit: NASA/JPL

Source: NASA/JPL - Mars Exploration Rovers - Spirit

What once would have taken one sol (or day) is now going to take Opportunity two sols. With age often comes a slower pace and, although JPL engineers have brilliantly figured out a solution to a potentially mission-cramping problem, their "senior" rover must move cautiously to preserve herself.

An encoder on the rock abrasion tool (RAT) is no longer working. The encoder indicates when the grinding teeth have detected a rock surface. However, another of its vital functions - being able to detect stalls - is no longer working. Stalls may indicate a problem for the RAT (for example a surface that is too tough to grind). If the tool stalls and that stall is not detected, the tool will continue to draw a current in an effort to keep moving, threatening to overheat and ruin the instrument.

When you are drilling, say, into a wall, if you hit an obstacle, the drill might jerk and damage the wall or the tool itself. This is a situation engineers are trying to avoid with Opportunity. After all, the rover has many more rocks to examine.

As they have done throughout both rovers' amazing over three-year run, engineers have taken the challenge to the testbed in order to come up with a solution or, in engineer-ease, a "work around."

"We are very fortunate that the encoder failed on the RAT grind motor because it is one of the few motors on the rover that we can safely operate without an encoder," said rover driver and technical lead for the RAT anomaly Dr. Ash**ey Trebi-Ollennu. "However, during RAT operations, an abrupt contact of the RAT grinding bit with a rock can cause the RAT grind motor to stall or kick back and result in damage to the IDD, or rover arm. This is a situation we are trying to avoid because the IDD carries two-thirds of the science payload."

Image credit: NASA/JPL-Caltech

Source: NASA/JPL - Mars Exploration Rovers - The Mission

RNASA's Mars Exploration Rover Spirit has discovered evidence of an ancient volcanic explosion at "Home Plate," a plateau of layered bedrock approximately 2 meters (6 feet) high within the "Inner Basin" of Columbia Hills, at the rover's landing site in Gusev Crater. This is the first explosive volcanic deposit identified with a high degree of confidence by Spirit or its twin, Opportunity.

There is strong evidence that those layers are from a volcanic explosion, said Steve Squyres of Cornell University, Ithaca, N.Y. Squyres is principal investigator for the rovers' science instruments. The findings about volcanic activity are reported in a paper published in the May 4 issue of the journal Science.


Image above: The lower coarse-grained unit shows granular textures
toward the bottom of the image and massive textures. Also shown in this
false-color view is a feature interpreted to be a "bomb sag," which is 4
centimeters across.
Image Credit: NASA/JPL-Caltech/USGS/Cornell

Evidence shows the area near Home Plate is dominated by basaltic rocks. "When basalt erupts, it often does so as very fluid lava, rather than erupting explosively," Squyres said. "One way for basaltic lava to cause an explosion is for it to come into contact with water - it's the pressure from the steam that causes it to go boom."

Scientists suspect that the explosion that formed Home Plate may have been caused by an interaction of basaltic lava and water. "When you look at composition of the rocks in detail, there are hints that water may have been involved," Squyres said. One example is the high chlorine content of the rocks, which might indicate that basalt had come into contact with a brine.

One of the strongest pieces of evidence for an explosive origin for Home Plate is a "bomb sag" preserved in layered rocks on the lower slopes of the plateau. Bomb sags form in volcanic explosions on Earth when rocks ejected skyward by the explosion fall into soft deposits, deforming them as they land.

Spirit arrived at Home Plate in February 2006 and spent several months exploring it in detail before driving to "Low Ridge" to pass the Martian winter. Spirit has now returned to Home Plate to continue exploration there. "We decided to go back to Home Plate, once the Martian winter ended, because it is one of the most interesting places that we've found on Gusev Crater," Squyres said. "Last year we primarily explored the northern and eastern sides of it. This time we're hoping to get to the southern and western sides." Spirit's continued exploration of Home Plate will focus largely on testing the idea that water was involved in its formation process.


Image above: Spirit's view of "Home Plate."
Image Credit: NASA/JPL-Caltech/USGS/Cornell

Spirit and Opportunity are in their fourth year of exploring Mars. They successfully completed their three-month prime missions in April 2004, and the missions have been extended four times. As of April 26, Spirit had spent 1,177 sols, or Martian days, on the surface of Mars and had driven 7,095 meters (4.4 miles), and Opportunity had spent 1,157 sols and driven 10,509 meters (6.5 miles).

"Considering their age, both rovers are in good health. All science instruments are functioning and continuing to return superb science data," said John Callas, project manager of the Mars Exploration Rover mission at NASA's Jet Propulsion Laboratory, Pasadena, Calif.

JPL manages the Mars Exploration Rover project for NASA's Science Mission Directorate. JPL is a division of the California Institute of Technology in Pasadena.

For images and information about the rovers and their discoveries on the Web, visit: http://www.nasa.gov/rovers or http://marsrovers.jpl.nasa.gov.

For information about NASA and agency programs on the Internet, visit: http://www.nasa.gov


Media contact: Guy Webster/Natalie Godwin 818-354-6278/0850
Jet Propulsion Laboratory, Pasadena, Calif.

Dwayne Brown 202-358-1726
NASA Headquarters, Washington

2007-0510

Source: NASA - Missions _ Mars Rovers

Evidence of Volcanic Explosion

05.03.07

The lower coarse-grained unit shows granular textures toward the bottom of the image and massive textures. Also shown is a feature interpreted to be a "bomb sag," which is 4 centimeters across. This false color image was obtained using Spirit's panoramic camera.

+ High resolution JPEG

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

Source: NASA - Missions - Mars Rovers - Images

Layers at Home Plate

05.03.07

NASA's Mars Exploration Rover Spirit acquired this high-resolution view of intricately layered exposures of rock while parked on the northwest edge of the bright, semi-circular feature known as "Home Plate." The rover was perched at a 27-degree upward tilt while creating the panorama, resulting in the "U" shape of the mosaic. (A) The northern edge of Home Plate, (B) the coarse-grained lower unit, © the fine-grained upper unit. Spirit acquired 246 separate images of this scene using 6 different filters on the panoramic camera (Pancam) during the rover's Martian days, or sols, 748 through 751 (Feb. 9 through Feb. 12, 2006). The field of view covers 160 degrees of terrain around the rover.

An un-labeled version of full panorama is available:
+ High resolution JPEG

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

Source: NASA - Missions - Mars Rovers - Images

Spirit's Recent Travels

05.03.07

"Home Plate" is viewed from orbit. North is at the top and the path followed by the rover Spirit is shown. This image was taken by the Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment camera on November 22, 2006. Spirit parked at "Low Ridge" with an 11-degree northerly tilt to maximize sunlight on the solar panels during the southern winter season. The original image is catalogued as PSP_001513_1655_red.

Image Credit: NASA/JPL-Caltech/Univ. of Arizona

High resolution (763kb): + Without annotation | + With annotation

Source: NASA - Missions - Mars Rovers - Images

Spirit Examines Nodule-Rich Rock

On sol 1177, Spirit used the rock abrasion tool to brush away dust covering the surface of a small, nodule-rich outcrop nicknamed "Slide" at the edge of the circular plateau known as "Home Plate." This image mosaic, acquired by the microscopic imager, shows the nature of the weathered outcrop surface, just beneath the dust coating. The science team has a special interest in the rocks in this general area, some of which show the highest silica content yet measured on Mars.

Image credit: NASA/JPL-Caltech/Cornell

Spirit Returns to 'Home Plate'

Spirit is presently parked at the edge of "Home Plate," a light-toned, bowl-shaped feature that exposes inward-dipping, thin-bedded volcanic sediments. The curving outcrops in this image hint at the inward-dipping geometry of the rocks. Spirit took this mosaic of images with the panoramic camera on the rover's 1,176th sol, or Martian day, of exploration.

Image credit: NASA/JPL-Caltech/Cornell

Source: NASA/JPL - Mars Exploration Rovers - Spirit

PASADENA, Calif. - A patch of Martian soil analyzed by NASA's rover Spirit is so rich in silica that it may provide some of the strongest evidence yet that ancient Mars was much wetter than it is now. The processes that could have produced such a concentrated deposit of silica require the presence of water.

Members of the rover science team heard from a colleague during a recent teleconference that the alpha particle X-ray spectrometer, a chemical analyzer at the end of Spirit's arm, had measured a composition of about 90 percent pure silica for this soil.


Image above: NASA's Spirit rover has found a patch of bright-toned
soil so rich in silica that scientists propose water must have been involved
in concentrating it.
Image credit: NASA/JPL-Caltech/Cornell

"You could hear people gasp in astonishment," said Steve Squyres of Cornell University, Ithaca, N.Y., principal investigator for the Mars rovers' science instruments. "This is a remarkable discovery. And the fact that we found something this new and different after nearly 1,200 days on Mars makes it even more remarkable. It makes you wonder what else is still out there."

Spirit's miniature thermal emission spectrometer observed the patch, and Steve Ruff of Arizona State University, Tempe, noticed that its spectrum showed a high silica content. The team has laid out plans for further study of the soil patch and surrounding deposits.

Exploring a low range of hills inside a Connecticut-sized basin named Gusev Crater, Spirit had previously found other indicators of long-ago water at the site, such as patches of water-bearing, sulfur-rich soil; alteration of minerals; and evidence of explosive volcanism.

"This is some of the best evidence Spirit has found for water at Gusev," said Albert Yen, a geochemist at NASA's Jet Propulsion Laboratory, Pasadena, Calif. One possible origin for the silica could have been interaction of soil with acid vapors produced by volcanic activity in the presence of water. Another could have been from water in a hot spring environment. The latest discovery adds compelling new evidence for ancient conditions that might have been favorable for life, according to members of the rover science team.


Image above: Spirit has found a patch of
bright-toned, silicate-rich soil.
Image credit: NASA/JPL-Caltech/Cornell

David Des Marais, an astrobiologist at NASA's Ames Research Center, Moffett Field, Calif., said, "What's so exciting is that this could tell us about environments that have similarities to places on Earth that are clement for organisms."

Spirit and its twin rover, Opportunity, completed their original three-month prime missions in April 2004. Both are still operating, though showing signs of age. One of Spirit's six wheels no longer rotates, so it leaves a deep track as it drags through soil. That churning has exposed several patches of bright soil, leading to some of Spirit's biggest discoveries at Gusev, including this recent discovery.

Doug McCuistion, director of NASA's Mars Exploration Program, said, "This unexpected new discovery is a reminder that Spirit and Opportunity are still doing cutting-edge exploration more than three years into their extended missions. It also reinforces the fact that significant amounts of water were present in Mars' past, which continues to spur the hope that we can show that Mars was once habitable and possibly supported life."

The newly discovered patch of soil has been given the informal name "Gertrude Weise," after a player in the All-American Girls Professional Baseball League, according to Ray Arvidson of Washington University in St. Louis, deputy principal investigator for the rovers.

"We've looked at dozens of disturbed soil targets in the rover tracks, and this is the first one that shows a high silica signature," said Ruff, who last month proposed using Spirit's miniature thermal emission spectrometer to observe this soil. That instrument provides mineral composition information about targets viewed from a distance. The indications it found for silica in the overturned soil prompted a decision this month to drive Spirit close enough to touch the soil with the alpha particle X-ray spectrometer. Silica commonly occurs on Earth as the crystalline mineral quartz and is the main ingredient in window glass. The Martian silica at the Gertrude Weise patch is non-crystalline, with no detectable quartz.

Spirit worked within about 50 yards or meters of the Gertrude Weise area for more than 18 months before the discovery was made. "This discovery has driven home to me the value of in-depth, careful exploration," Squyres said. "This is a target-rich environment, and it is a good thing we didn't go hurrying through it."

Meanwhile, on the other side of the planet, Opportunity has been exploring Victoria Crater for about eight months. "Opportunity has completed the initial survey of the crater's rim and is now headed back to the area called Duck Bay, which may provide a safe path down into the crater," said John Callas, project manager for the rovers at JPL.

JPL, a division of the California Institute of Technology, Pasadena, manages the Mars Exploration Rover project for NASA's Science Mission Directorate. For images and information about the rovers, visit http://www.nasa.gov/rovers.


Media contact: Natalie Godwin/Guy Webster 818-354-0850/6278
Jet Propulsion Laboratory, Pasadena, Calif.

Dwayne Brown/Tabatha Thompson 202-358-1726/3895
NASA Headquarters, Washington

2007-061

Source: NASA - Missions - Mars Rovers

Silica-Rich Soil in Gusev Crater

05.21.07

NASA's Mars Exploration Rover Spirit has found a patch of bright-toned soil so rich in silica that scientists propose water must have been involved in concentrating it.

The silica-rich patch, informally named "Gertrude Weise" after a player in the All-American Girls Professional Baseball League, was exposed when Spirit drove over it during the 1,150th Martian day, or sol, of Spirit's Mars surface mission (March 29, 2007). One of Spirit's six wheels no longer rotates, so it leaves a deep track as it drags through soil. Most patches of disturbed, bright soil that Spirit had investigated previously are rich in sulfur, but this one has very little sulfur and is about 90 percent silica.

Spirit's panoramic camera imaged the bright patch through various filters on Sol 1,158 (April 6). This approximately true-color image combines images taken through three different filters. The track of disturbed soil is roughly 20 centimeters (8 inches) wide.

Spirit's miniature thermal emission spectrometer, which can assess a target's mineral composition from a distance, examined the Gertrude Weise patch on Sol 1,172 (April 20). The indications it found for silica in the overturned soil prompted a decision to drive Spirit close enough to touch the soil with the alpha particle X-ray spectrometer, a chemical analyzer at the end of Spirit's robotic arm. The alpha particle X-ray spectrometer collected data about this target on sols 1,189 and 1,190 (May 8 and May 9) and produced the finding of approximately 90 percent silica.

Silica is silicon dioxide. On Earth, it commonly occurs as the crystalline mineral quartz and is the main ingredient in window glass. The Martian silica at Gertrude Weise is non-crystalline, with no detectable quartz.

In most cases, water is required to produce such a concentrated deposit of silica, according to members of the rover science team. One possible origin for the silica could have been interaction of soil with acidic steam produced by volcanic activity. Another could have been from water in a hot spring environment.

Image Credit: NASA/JPL/Cornell

+ Higher resolution JPEG (241Kb)

Source: NASA - Missions - Mars Rovers - Images

Silica-Rich Soil Found by Spirit

05.21.07

NASA's Mars Exploration Rover Spirit has found a patch of bright-toned soil so rich in silica that scientists propose water must have been involved in concentrating it.

The silica-rich patch, informally named "Gertrude Weise" after a player in the All-American Girls Professional Baseball League, was exposed when Spirit drove over it during the 1,150th Martian day, or sol, of Spirit's Mars surface mission (March 29, 2007). One of Spirit's six wheels no longer rotates, so it leaves a deep track as it drags through soil. Most patches of disturbed, bright soil that Spirit had investigated previously are rich in sulfur, but this one has very little sulfur and is about 90 percent silica.

This image is a approximately true-color composite of three images taken through different filters by Spirit's panoramic camera on Sol 1,187 (May 6). The track of disturbed soil is roughly 20 centimeters (8 inches) wide.

Spirit's miniature thermal emission spectrometer, which can assess a target's mineral composition from a distance, examined the Gertrude Weise patch on Sol 1,172 (April 20). The indications it found for silica in the overturned soil prompted a decision to drive Spirit close enough to touch the soil with the alpha particle X-ray spectrometer, a chemical analyzer at the end of Spirit's robotic arm. The alpha particle X-ray spectrometer collected data about this target on sols 1,189 and 1,190 (May 8 and May 9) and produced the finding of approximately 90 percent silica.

Silica is silicon dioxide. On Earth, it commonly occurs as the crystalline mineral quartz and is the main ingredient in window glass. The Martian silica at Gertrude Weise is non-crystalline, with no detectable quartz.

In most cases, water is required to produce such a concentrated deposit of silica, according to members of the rover science team. One possible origin for the silica could have been interaction of soil with acidic steam produced by volcanic activity. Another could have been from water in a hot spring environment.

Image Credit: NASA/JPL/Cornell

+ Higher resolution JPEG (790Kb)

Source: NASA - Missions - Mars Rovers - Images

Opportunity recently completed work on soil exposures north of the rim of Victoria Crater where winds channeled by alcoves have produced alternating light and dark streaks. The rover finished in-situ analyses with measurements at a target known as "Alicante," where there appears to be a concentration of dark sand on the downwind side of a rock, on sol 1149 (April 18, 2007). Analysis continues of data collected from this and other sites.

In addition, strong winds perhaps associated with channeling caused by the crater's jagged rim may have contributed to deck-cleaning events for Opportunity. On two separate occasions, sols 1153 (April 22, 2007) and 1158 (April 27, 2007), the solar array power increased significantly. In fact, the power level of 848 watt-hours, reached on sol 1160 (April 29, 2007), was the highest measured since about sol 300 (Nov. 26, 2004), early in the mission. (A watt-hour is the amount of power needed to light a 100-watt bulb for one hour.)

This orbital view was acquired by the High-Resolution Imaging Science Experiment camera on the Mars Reconnaissance Orbiter.

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

For more images like this see "Where are they now?"

Source: NASA/JPL - Mars Exploration Rovers - Opportunity

Like Sun Belt retirees who complain about cold weather, NASA's Mars rovers are becoming less tolerant of temperature changes with age.


Image above: Air Temperatures -- Spirit
Temperatures in the shade for Spirit ranged from highs of about 35 degrees C. (95 degrees F.) in summer to lows of -90 degrees C. (-130 degrees F.) in winter. In the background is a panoramic camera image of sunset on Mars.
Image credit: NASA/JPL-Caltech/Cornell/NMMNH
+ View larger image

Near the martian equator, where the rovers are exploring opposite sides of the red planet, highs and lows make Earth temperatures look downright tropical. Temperatures often differ by more than 100 degrees Celsius. That's a change of 180 degrees Fahrenheit -- the equivalent of having the temperature drop from a high of 70 degrees F. at midday to minus 110 degrees F. the same night. That would be like going from a beach in Hawaii to the South Pole in mid-winter ... every day!

Extreme Planet

Though both rovers are exploring Mars well beyond their initial 90-day missions, electrical connections and moving parts are showing signs of temperature-related fatigue.


Image above: Air Temperatures -- Opportunity
Temperatures in the shade for Opportunity ranged from about 30 degrees C. (86 degrees F.) in summer to minus 80 degrees C. (-112 degrees F.) in winter. The background panorama shows a false-color view of dunes at the bottom of Endurance Crater.
Image credit: NASA/JPL-Caltech/Cornell/NMMNH
+ View larger image

"Every day we have a huge thermal cycle," notes Jake Matijevic, chief of the rover engineering team. "That causes the solder in electrical connections to expand and contract until it breaks."

Seasonal Change

During their exploration of Mars, the rovers have recorded temperatures ranging from midday highs of about 35 degrees C. (95 degrees F.) in spring and summer to nighttime lows of about minus 110 degrees C. (minus 166 degrees F.) in winter. Spirit has experienced greater swings in temperature because its location is farther from the martian equator, which puts it seasonally closer to or farther from the Sun than Opportunity.


Image above: Solar Panel Temperatures -- Spirit
Summer temperatures on Spirit's solar arrays have reached summertime highs of more than 30 degrees C. and winter lows of about minus 110 degrees C. The image in the background shows the rover's view of "Husband Hill" after cliimbing down from the top.
Image credit: NASA/JPL-Caltech/Cornell/NMMNH
+ View larger image

Three Years of Data

Rover engineer Dan Porter has been tracking temperatures recorded by 50 or so sensors on each of the rovers since shortly after they landed on Mars in January 2004. The results are not only of interest to scientists, they're a favorite of human audiences as well.


Image above: Solar Panel Temperatures -- Opportunity
Nighttime temperatures on Opportunity's solar panels fell within a fairly stable range of about minus 90 degrees C. (-130 degrees F.) to minus 100 degrees C. (-148 degrees F.) most nights. Daytime temperatures reached a high of around 30 degrees C. (86 degrees F.) in the summer. In the background of the chart is an outcrop known as "Cape St. Mary" in Victoria Crater.
Image credit: NASA/JPL-Caltech/Cornell/NMMNH
+ View larger image

"People ask about this all the time," says New Mexico geologist Larry Crumpler, a member of the Mars rover science team who created the charts showing monthly average temperatures superimposed on panoramic-camera images from each of the rovers. "These plots of daily temperature are destined to become an important part of all my public outreach talks."

Cold vs. Colder

Just as on Earth, temperatures on Mars are not uniform everywhere. Objects exposed to direct sunlight are apt to be warmer than those in the shade. Some objects retain heat better than others. A source of relative warmth on Mars is rocky terrain, because it retains heat better than sandy terrain.


Image above: Colder in the Shade
On Mars as on Earth, surfaces shaded from sunlight are more likely to develop a veneer of frost. This pair of images taken by the Compact Reconnaissance Imaging Spectrometer for Mars, on board the Mars Reconnaissance Orbiter, shows water frost in shaded areas and carbon dioxide frost in only the coldest of those.
Image credit: NASA/JPL-Caltech/JHU APL.
+ View larger image

A solar panel is sort of like a "warm wall in mid-winter," says Crumpler. Components beneath the solar panels, such as the hazard avoidance cameras, are closer in temperature to the martian air. Unlike Earth, Mars does not have a thick, atmospheric blanket to seal in warmth by night or minimize the Sun's heat by day.

Wear and Tear

Engineers have traced stalls in a shoulder joint on Opportunity's robotic arm to a broken electrical wire. The shoulder motor has experienced greater temperature swings than other parts because of its location beside a heater that has been stuck in the "on" position since shortly after landing.


Image above: Frost on Mars Rover
Opportunity discovered frost on the rover's calibration target in October 2004.
Image credit: NASA/JPL-Caltech/Cornell
+ View larger image

Notes Matijevic, "Our theory is that one of the wires in the electrical coil broke free and di