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Mars Polar Lander
A bottom view of the Mars Po
| Description |
A bottom view of the Mars Polar Lander spacecraft. The spacecraft will travel 10 months from Earth to Mars to land near the southern polar cap in December 1999 and carry out a three- month mission to search for traces of subsurface water in this frozen, layered terrain. The lander carries three scientific packages: the Mars descent imager, furnished by Malin Space Science Systems, Inc., which will view the landing site at increasingly higher resolution, the atmospheric lidar experiment, provided by Russia's Space Research Institute, which will measure the presence and height of atmospheric hazes, along with a miniature microphone provided by The Planetary Society, to record the sounds of Mars, and the Mars Volatile and Climate Surveyor science package. The mission is part of NASA's Mars Surveyor program, a sustained program of robotic exploration of the red planet, managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, Washington, DC. Lockheed Martin Astronautics is NASA's industrial partner in the mission. ##### |
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Mars Polar Lander
A top view of the Mars Polar
| Description |
A top view of the Mars Polar Lander spacecraft. The spacecraft will travel 10 months from Earth to Mars to land near the southern polar cap in December 1999 and carry out a three- month mission to search for traces of subsurface water in this frozen, layered terrain. The lander carries three scientific packages: the Mars descent imager, furnished by Malin Space Science Systems, Inc., which will view the landing site at increasingly higher resolution, the atmospheric lidar experiment, provided by Russia's Space Research Institute, which will measure the presence and height of atmospheric hazes, along with a miniature microphone provided by The Planetary Society, to record the sounds of Mars, and the Mars Volatile and Climate Surveyor science package. The mission is part of NASA's Mars Surveyor program, a sustained program of robotic exploration of the red planet, managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, Washington, DC. Lockheed Martin Astronautics is NASA's industrial partner in the mission. ##### |
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1998 Mars Polar Lander
The Mars Surveyor '98 Polar
5/27/98
| Date |
5/27/98 |
| Description |
The Mars Surveyor '98 Polar Lander is shown during recent deployment and testing of its surface solar panels. The spacecraft will travel 10 months from Earth to Mars to land near the southern polar cap in December 1999 and carry out a three- month mission to search for traces of subsurface water in this frozen, layered terrain. The lander carries three scientific packages: the Mars descent imager, furnished by Malin Space Science Systems, Inc., which will view the landing site at increasingly higher resolution, the atmospheric lidar experiment, provided by Russia's Space Research Institute, which will measure the presence and height of atmospheric hazes, along with a miniature microphone provided by The Planetary Society, to record the sounds of Mars, and the Mars Volatile and Climate Surveyor science package. The mission is part of NASA's Mars Surveyor program, a sustained program of robotic exploration of the red planet, managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, Washington, DC. Lockheed Martin Astronautics is NASA's industrial partner in the mission. Photo copyright 1998, Lockheed Martin ##### |
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1998 Mars Climate Orbiter
The Mars Surveyor '98 Climat
5/27/98
| Date |
5/27/98 |
| Description |
The Mars Surveyor '98 Climate Orbiter, which is entering the final stages of testing this summer at Lockheed Martin Astronautics, Denver, CO, is shown here during acoustic tests that simulate launch conditions. The orbiter will conduct a two- year primary mission to profile the Martian atmosphere and map the surface. To carry out these scientific objectives, the spacecraft will carry a rebuilt version of the pressure-modulated infrared radiometer, lost with the Mars Observer spacecraft, and a miniaturized dual camera system the size of a pair of binoculars, provided by Malin Space Science Systems, Inc., San Diego, CA. During its primary mission, the orbiter will monitor Mars' atmosphere and surface globally on a daily basis for one Martian year (two Earth years), observing the appearance and movement of atmospheric dust and water vapor, as well as characterizing seasonal changes of the planet's surface. Imaging of the surface morphology will also provide important clues about the planet's climate in its early history. The mission is part of NASA's Mars Surveyor program, a sustained program of robotic exploration of the red planet, managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, Washington, DC. Lockheed Martin Astronautics is NASA's industrial partner in the mission. Photo copyright 1998, Lockheed Martin ##### |
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Mars Polar Lander
The Mars Polar Lander is sho
| Description |
The Mars Polar Lander is shown on the surface of Mars. The spacecraft will travel 10 months from Earth to Mars to land near the southern polar cap in December 1999 and carry out a three- month mission to search for traces of subsurface water in this frozen, layered terrain. The lander carries three scientific packages: the Mars descent imager, furnished by Malin Space Science Systems, Inc., which will view the landing site at increasingly higher resolution, the atmospheric lidar experiment, provided by Russia's Space Research Institute, which will measure the presence and height of atmospheric hazes, along with a miniature microphone provided by The Planetary Society, to record the sounds of Mars, and the Mars Volatile and Climate Surveyor science package. The mission is part of NASA's Mars Surveyor program, a sustained program of robotic exploration of the red planet, managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, Washington, DC. Lockheed Martin Astronautics is NASA's industrial partner in the mission. ##### |
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Olympus Mons, 1998
| title |
Olympus Mons, 1998 |
| date |
04.25.1998 |
| description |
Olympus Mons is a mountain of mystery. Taller than three Mount Everests and about as wide as the entire Hawaiian Island chain, this giant volcano is nearly as flat as a pancake. That is, its flanks typically only slope 20 to 50. The Mars Orbiter Camera (MOC) obtained this spectacular wide-angle view of Olympus Mons on Mars Global Surveyor's 263rd orbit, around 10:40 p.m. PDT on April 25, 1998. In the view presented here, north is to the left and east is up. The spacecraft was traveling from north to south (left to right). Although the camera looks straight down (towards the nadir) and cannot be pointed to the side, the wide angle camera has such a large field of view (it sees from horizon to horizon) that, in effect, it provides side looking views. Unlike some other MOC images, that have had to be warped to provide a view as if seen from a certain direction and altitude, this image shows what the camera saw without additional processing. It is easy to imagine that you are looking out a window at the surface of Mars from about 900 km (560 miles) up. The image was taken on a cool, crisp winter morning. The west side of the volcano (lower portion of view, above) was clear and details on the surface appear very sharp. The skies above the plains to the east of Olympus Mons (upper portion of view) were cloudy. Clouds were lapping against the lower east flanks of this 26 kilometers (16 miles) high volcano, but the summit skies were clear. When Mars Global Surveyor attains its Mapping Orbit in March 1999, the MOC wide angle camera system will be used to make daily, global maps of martian clouds and weather systems. The wide angle images will resemble weather satellite pictures of Earth, and will help the Mars science teams plan their observations and test computer-driven Mars weather prediction models. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO. Image Note: This color picture was made using MOC red wide angle image 26301 and blue wide angle image 26302. The green channel was synthesized by averaging the red and blue bands. Color is not the true color of Mars as it would appear to the human eye (the actual colors would be more pale and contrast more subdued) *Image Credit*: NASA/JPL/Malin Space Science Systems |
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Mars River Delta?
| title |
Mars River Delta? |
| description |
A high-resolution TIFF file of this image is available at http://photojournal.jpl.nasa.gov/catalog/PIA04869. Details in a fan-shaped deposit discovered by NASA's Mars Global Surveyor orbiter provide evidence that some ancient rivers on Mars flowed for a long time, not just in brief, intense floods. The apron of debris filling the middle of this picture from the spacecraft's Mars Orbiter Camera is a hardened and eroded distributory fan, a type of geological feature that includes river deltas and alluvial fans. Sediments transported through valleys by water on early Mars formed the 13-kilometer-long (8-mile) deposit in the distant past, when it was still possible for liquid water to flow across the martian surface. Mars Orbiter Camera team members published discovery of this feature in the online edition of the journal Science. What is important about it? First, it provides unequivocal evidence that some valleys on Mars experienced persistent flow over considerable periods of time, as rivers do on Earth. Second, because the fan is today a deposit of sedimentary rock, it demonstrates that some sedimentary rocks on Mars were deposited in a liquid environment. Third, the fan's general shape, the pattern of its channels, and its low slopes provide circumstantial evidence that the feature was an actual delta -- that is, a deposit made when a river or stream enters a body of water. If so, this landform is a strong indicator that some craters and basins on Mars once held lakes. Hundreds of other locations on Mars where valleys enter craters and basins have been imaged by the Mars Orbiter Camera, but none has shown landforms like those presented here. The picture is a mosaic of images acquired between August 2000 and September 2003. The area covered 14 kilometer (8.7 miles) by 19.3 kilometers (12 miles). North is up. Sunlight illuminates the scene from the left. The spacecraft's narrow-angle camera takes grayscale images, the color added is based on information from a camera on Mars Odyssey. The fan is in an unnamed crater that is 64 kilometers (40 miles) in diameter, at 24.3 degrees south latitude, 33.5 degrees west longitude. The crater lies northeast of a larger one named Holden Crater. The fan is a fossil landform. That is, it is an eroded remnant of a somewhat larger and thicker deposit. The originally loose sediment was turned to rock and then eroded over time to present the features seen today. The channels through which sediment was transported are no longer present. Instead, only their floors remain, and these have been elevated by erosion so that former channels now stand as ridges. The floors of former channels became inverted in this way because they were more resistant to the forces of erosion, indicating they either were more strongly cemented than surrounding materials, or they have more coarse grains (which are harder to remove), or both. *Image Credit*: NASA/JPL/Malin Space Science Systems |
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New Gullies on Martian Sand
| title |
New Gullies on Martian Sand Dune |
| description |
As part of extended-mission science investigation using the Mars Orbiter Camera on NASA's Mars Global Surveyor spacecraft, the camera team is re-imaging many locations where previous observations revealed gullies. The intent is to see if gully-forming processes are operating on Mars at the present time. The team has found one location where a new gully formed on a dune in an unnamed crater in the Hellespontus region of Mars, west of the Hellas Basin. This pair of narrow-angle images from the Mars Orbiter Camera shows the dune as it appeared on July 17, 2002, (left) and as it appeared on April 27, 2005, (right). The nearly three Earth years of intervening time amount to about 1.4 Mars years. During this period, a couple of gullies formed on the dune slip face. It is critical to recognize that the 2002 image was obtained at a time of year when the incident sunlight was coming in from a lower angle, relative to the horizon, than in the 2005 image. If the gullies had been present in 2002, their appearance would be sharper and more pronounced than they are in the 2005 image. The gullies simply did not exist on July 17, 2002. The steep walls of the gully alcove and channels suggests that the sand in this dune is somewhat cohesive, an observation common among martian sand dunes seen by the Mars Orbiter Camera over the past eight years. Image Credit: NASA/JPL/MSSS |
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Evidence of Martian Quakes
| title |
Evidence of Martian Quakes |
| description |
One of the many mysteries associated with martian geology is the origin of gullies found at latitudes poleward of 30 degrees latitude. Most of these gullies are found within craters or other depressions, and appear to be related to the bedrock. Several hypotheses have been proposed for their origin, including groundwater seepage and melting at the base of a dust-mantled snow pack. Some middle-latitude gullies are found on sand dunes. These gullies appear to be different from those found on the slopes of craters, but generally have been interpreted to form by similar processes. In the present martian environment, it is difficult to introduce water to the surface. The temperature and atmospheric pressure may permit water to exist, but the rate of heating of the ground and atmosphere, and the amount of energy available to warm the ground or melt snow, are not conducive to such processes. An alternative process of gully formation on these sand dunes involves frozen carbon dioxide trapped in the winter by windblown sand, then subliming rapidly enough for the escaping carbon-dioxide gas to make the sand flow as a gully-cutting fluid. As part of extended-mission science investigation using the Mars Orbiter Camera on NASA's Mars Global Surveyor spacecraft, the camera team is re-imaging many locations where previous observations revealed gullies. The intent is to see if gully-forming processes are operating on Mars at the present time. The team has found one location where a new gully formed on a dune in an unnamed crater in the Hellespontus region of Mars, west of the Hellas Basin. This pair of narrow-angle images from the Mars Orbiter Camera shows the dune as it appeared on July 17, 2002, (left) and as it appeared on April 27, 2005, (right). The nearly three Earth years of intervening time amount to about 1.4 Mars years. During this period, a couple of gullies formed on the dune slip face. It is critical to recognize that the 2002 image was obtained at a time of year when the incident sunlight was coming in from a lower angle, relative to the horizon, than in the 2005 image. If the gullies had been present in 2002, their appearance would be sharper and more pronounced than they are in the 2005 image. The gullies simply did not exist on July 17, 2002. The steep walls of the gully alcove and channels suggests that the sand in this dune is somewhat cohesive, an observation common among martian sand dunes seen by the Mars Orbiter Camera over the past eight years. Wider context for the dune is shown in a mosaic of two images from the Thermal Emission Imaging System on NASA's Mars Odyssey orbiter, encompassing the dark-toned sand dune field on the floor of a crater located near 49.8 degrees south latitude, 325.4 degrees west longitude. In this image, north is approximately up and sunlight illuminates the scene from the upper left. More information about this image can be found at: http://photojournal.jpl.nasa.gov/catalog/PIA04290 |
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Mars Climate Orbiter
| Title |
Mars Climate Orbiter |
| Full Description |
The Mars Surveyor '98 Climate Orbiter is shown here during acoustic tests that simulate launch conditions. The orbiter was to conduct a two year primary mission to profile the Martian atmosphere and map the surface. To carry out these scientific objectives, the spacecraft carried a rebuilt version of the pressure modulated infrared radiometer, lost with the Mars Observer spacecraft, and a miniaturized dual camera system the size of a pair of binoculars, provided by Malin Space Science Systems, Inc., San Diego, California. During its primary mission, the orbiter was to monitor Mars atmosphere and surface globally on a daily basis for one Martian year (two Earth years), observing the appearance and movement of atmospheric dust and water vapor, as well as characterizing seasonal changes of the planet's surface. Imaging of the surface morphology would also provide important clues about the planet's climate in its early history. The mission was part of NASA's Mars Surveyor program, a sustained program of robotic exploration of the red planet, managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, Washington, DC. Lockheed Martin Astronautics was NASA's industrial partner in the mission. Unfortunately, Mars Climate Orbiter burned up in the Martian atmosphere on September 23, 1999, due to a metric conversion error that caused the spacecraft to be off course. |
| Date |
05/27/1998 |
| NASA Center |
Jet Propulsion Laboratory |
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Evidence for Recent Liquid W
| Title |
Evidence for Recent Liquid Water on Mars |
| Full Description |
Newton Crater is a large basin formed by an asteroid impact that probably occurred more than 3 billion years ago. It is approximately 287 kilometers (178 miles) across. The picture shown here (top) highlights the north wall of a specific, smaller crater located in the southwestern quarter of Newton Crater (above). The crater of interest was also formed by an impact, it is about 7 km (4.4 mi) across, which is about 7 times bigger than the famous Meteor Crater in northern Arizona in North America. The north wall of the small crater has many narrow gullies eroded into it. These are hypothesized to have been formed by flowing water and debris flows. Debris transported with the water created lobed and finger-like deposits at the base of the crater wall where it intersects the floor (bottom center top image). Many of the finger-like deposits have small channels indicating that a liquid, most likely water, flowed in these areas. Hundreds of individual water and debris flow events might have occurred to create the scene shown here. Each outburst of water from higher up on the crater slopes would have constituted a competition between evaporation, freezing, and gravity. The individual deposits at the ends of channels in this MOC image mosaic were used to get a rough estimate of the minimum amount of water that might be involved in each flow event. This is done first by assuming that the deposits are like debris flows on Earth. In a debris flow, no less than about 10% (and no more than 30%) of their volume is water. Second, the volume of an apron deposit is estimated by measuring the area covered in the MOC image and multiplying it by a conservative estimate of thickness, 2 meters (6.5 feet). For a flow containing only 10% water, these estimates conservatively suggest that about 2.5 million liters (660,000 gallons) of water are involved in each event, this is enough to fill about 7 community-sized swimming pools or enough to supply 20 people with their water needs for a year. The Mars Orbiter Camera (MOC) high resolution view is located near 41.1S, 159.8W and is a mosaic of three different pictures acquired between January and May 2000. The MOC scene is illuminated from the left, north is up. |
| Date |
06/22/2000 |
| NASA Center |
Jet Propulsion Laboratory |
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Evidence for Recent Liquid W
| Title |
Evidence for Recent Liquid Water on Mars: Gullies |
| Full Description |
Gully landforms proposed to have been caused by geologically-recent seepage and runoff of liquid water on Mars are found in the most unlikely places. They typically occur in areas that are quite cold, well below freezing all year round. Like the old adage about moss on trees, nearly all of them form on slopes that face away from sunlight. Most of the gullies occur at latitudes between 30 and 70. The highest latitude at which martian gullies have been found is around 70-75 S on the walls of pits developed in the south polar pitted plains. If you were at this same latitude on Earth, you would be in Antarctica. This region spends much of the winter--which lasts approximately 6 months on Mars--in darkness and at temperatures cold enough to freeze carbon dioxide (around -130C or -200F). Nevertheless, gullies with very sharp, deep, v-shaped channels are seen on the pit walls. Based upon the locations of the tops of the channels on the slope shown here, the inferred site of liquid seepage is located at a layer in the pit wall about 1/3 of the way down from the top of the MOC image. The channels start wide and taper downslope. The area above the channels is layered and has been eroded by mass movement dry avalanching of debris--to form a pattern of chutes and ridges on the upper slope of the pit wall. The top layer appears to have many boulders in it (each about the size of a small house), these boulders are left behind on the upper slopes of the pit wall as debris is removed. |
| Date |
06/22/2000 |
| NASA Center |
Jet Propulsion Laboratory |
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Hubble's Sharpest View of Ma
| Title |
Hubble's Sharpest View of Mars |
| General Information |
What is an Early Release Observation? A photograph of a celestial object that demonstrates the performance of a new Hubble camera. The recently refurbished Hubble telescope obtained the sharpest view of Mars ever taken from Earth. This stunning portrait was taken with March 10, 1997, just before the Red Planet made one of its closest passes to Earth (about 60 million miles or 100 million kilometers). The Martian North Pole is at the top [near the center of the bright polar cap] and east is to the right. This view of Mars was taken on the last day of Martian spring in the Northern Hemisphere. |
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Hubble's Sharpest View of Ma
| Title |
Hubble's Sharpest View of Mars |
| General Information |
What is an Early Release Observation? A photograph of a celestial object that demonstrates the performance of a new Hubble camera. The recently refurbished Hubble telescope obtained the sharpest view of Mars ever taken from Earth. This stunning portrait was taken with March 10, 1997, just before the Red Planet made one of its closest passes to Earth (about 60 million miles or 100 million kilometers). The Martian North Pole is at the top [near the center of the bright polar cap] and east is to the right. This view of Mars was taken on the last day of Martian spring in the Northern Hemisphere. |
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Scientists Track "Perfect St
| Title |
Scientists Track "Perfect Storm" on Mars |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. Back to top [ #top ] |
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Scientists Track "Perfect St
| Title |
Scientists Track "Perfect Storm" on Mars |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. Back to top [ #top ] |
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Scientists Track "Perfect St
| Title |
Scientists Track "Perfect Storm" on Mars |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. Back to top [ #top ] |
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Scientists Track "Perfect St
| Title |
Scientists Track "Perfect Storm" on Mars |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. Back to top [ #top ] |
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Scientists Track "Perfect St
| Title |
Scientists Track "Perfect Storm" on Mars |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. Back to top [ #top ] |
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Scientists Track "Perfect St
| Title |
Scientists Track "Perfect Storm" on Mars |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. Back to top [ #top ] |
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Scientists Track "Perfect St
| Title |
Scientists Track "Perfect Storm" on Mars |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. Back to top [ #top ] |
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Scientists Track "Perfect St
| Title |
Scientists Track "Perfect Storm" on Mars |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. Back to top [ #top ] |
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Scientists Track "Perfect St
| Title |
Scientists Track "Perfect Storm" on Mars |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. Back to top [ #top ] |
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Scientists Track "Perfect St
| Title |
Scientists Track "Perfect Storm" on Mars |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. Back to top [ #top ] |
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Scientists Track "Perfect St
| Title |
Scientists Track "Perfect Storm" on Mars |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. Back to top [ #top ] |
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Scientists Track "Perfect St
| Title |
Scientists Track "Perfect Storm" on Mars |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. Back to top [ #top ] |
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High-Resolution MOC Image of
| Title |
High-Resolution MOC Image of Phobos' Face |
| Description |
This image of Phobos, the inner and larger of the two moons of Mars, was taken by the Mars Global Surveyor on August 19, 1998. The minimum distance between the spacecraft and Phobos was 1,080 kilometers (671 miles). Phobos was observed by both the Mars Orbiter Camera (MOC) and Thermal Emission Spectrometer (TES). This image is one of the highest resolution images (4 meters or 13 feet per picture element or pixel) ever obtained of the Martian satellite. The image shows several new features of this lumpy moon -- features that are associated with the prominent crater seen in the upper left quarter of the image. This is the largest crater on Phobos, Stickney, 10 kilometers (6 miles) in diameter. Individual boulders are visible on the near rim of the crater (D), and are presumed to be ejecta blocks from the impact that formed Stickney. Some of these boulders are enormous - more than 50 meters (160 feet) across. Also crossing at and near the rim of Stickney are shallow, elongated depressions called grooves. This crater is nearly half the size of Phobos and these grooves may be fractures caused by its formation. The far wall of the crater shows lighter and darker streaks going down the slopes (C). The presence of material of different brightness on the far crater slopes and in some of the grooves shows that the satellite is heterogeneous (that is, it is made of a mixture of different types of materials). The motion of debris down slopes is guided by gravity, which is only about 1/1000th that of the Earth -- e.g., a 68-kilogram (150- pound) person would weigh only about 57 grams (2 ounces) on Phobos. Previous images from the Viking spacecraft in the 1970's were not of sufficient resolution to show the effectiveness of gravity on Phobos in moving material down slopes. Malin Space Science Systems, Inc. and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Thermal Emission Spectrometer is operated by Arizona State University and was built by Raytheon Santa Barbara Remote Sensing. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO. |
| Date |
08.19.1998 |
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High-Resolution MOC Image of
| Title |
High-Resolution MOC Image of Phobos' Stickney Crater |
| Description |
This image of Phobos, the inner and larger of the two moons of Mars, was taken by the Mars Global Surveyor on August 19, 1998. This image is a close-up of the far wall of the Stickney crater, 10 kilometers (6 miles) in diameter, that is the largest crater on Phobos. This image shows lighter and darker streaks going down the slopes (C). The presence of material of different brightness on the far crater slopes and in some of the grooves shows that the satellite is heterogeneous (that is, it is made of a mixture of different types of materials). The motion of debris down slopes is guided by gravity, which is only about 1/1000th that of the Earth -- e.g., a 68-kilogram (150-pound) person would weigh only about 57 grams (2 ounces) on Phobos. Phobos was observed by both the Mars Orbiter Camera (MOC) and Thermal Emission Spectrometer (TES). This image is one of the highest resolution images (4 meters or 13 feet per picture element or pixel) ever obtained of the Martian satellite. Malin Space Science Systems, Inc. and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Thermal Emission Spectrometer is operated by Arizona State University and was built by Raytheon Santa Barbara Remote Sensing. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO. |
| Date |
08.19.1998 |
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The Martian Prime Meridian
| title |
The Martian Prime Meridian |
| Description |
On Earth, the longitude of the Royal Observatory in Greenwich, England is defined as the 'prime meridian,' or the zero point of longitude. Locations on Earth are measured in degrees east or west from this position. The prime meridian was defined by international agreement in 1884 as the position of the large 'transit circle', a telescope in the Observatory's Meridian Building. The transit circle was built by Sir George Biddell Airy, the 7th Astronomer Royal, in 1850. (While visual observations with transits were the basis of navigation until the space age, it is interesting to note that the current definition of the prime meridian is in reference to orbiting satellites and Very Long Baseline Interferometry (VLBI) measurements of distant radio sources such as quasars. This 'International Reference Meridian' is now about 100 meters east of the Airy Transit at Greenwich.) For Mars, the prime meridian was first defined by the German astronomers W. Beer and J. H. Mädler in 1830-32. They used a small circular feature, which they designated 'a,' as a reference point to determine the rotation period of the planet. The Italian astronomer G. V. Schiaparelli, in his 1877 map of Mars, used this feature as the zero point of longitude. It was subsequently named Sinus Meridiani ('Middle Bay') by Camille Flammarion. When Mariner 9 mapped the planet at about 1 kilometer (0.62 mile) resolution in 1972, an extensive 'control net' of locations was computed by Merton Davies of the RAND Corporation. Davies designated a 0.5-kilometer-wide crater (0.3 miles wide), subsequently named 'Airy-0' (within the large crater Airy in Sinus Meridiani) as the longitude zero point. (Airy, of course, was named to commemorate the builder of the Greenwich transit.) This crater was imaged once by Mariner 9 (the 3rd picture taken on its 533rd orbit, 533B03) and once by the Viking 1 orbiter in 1978 (the 46th image on that spacecraft's 746th orbit, 746A46), and these two images were the basis of the martian longitude system for the rest of the 20th Century. The Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) has attempted to take a picture of Airy-0 on every close overflight since the beginning of the MGS mapping mission. It is a measure of the difficulty of hitting such a small target that nine attempts were required, since the spacecraft did not pass directly over Airy-0 until almost the end of the MGS primary mission, on orbit 8280 (January 13, 2001). more information [ http://photojournal.jpl.nasa.gov/catalog/PIA03207 ] Photo Credit: NASA/JPL/Malin Space Science Systems |
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Strange Surfaces of Hellas P
| title |
Strange Surfaces of Hellas Planitia |
| Description |
Sometimes Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images show things that look very bizzare. Unique among the MOC images is a suite of pictures from northwestern Hellas Planitia, such as the example shown here. The seeming familiarity of many MOC images, such as those showing earth-like sand dunes or stream-like gullies might give the impression that it is pretty easy to understand what MOC images are telling us about the geology of Mars. Indeed, much of what has been found by MOC is both interpretable and profound---layers recording the planet's early geologic history, evidence for recent groundwater emerging at the surface, dust storms and frost patterns that indicate seasonal change. Howver, many martian landforms remain unexplained and may require years of study. This picture, acquired in late October 2000, appears to be a jumble of plates or layers exposed at the surface but subsequently covered by a thin mantle to give the scene a uniform brightness. What are these materials? Perhaps time and careful study will tell. The picture is illuminated from the upper left and covers an area 2.9 by 4.1 km (1.8 by 2.5 mi) near 39.7°S, 306.7°W. Photo Credit: NASA/JPL/Malin Space Science Systems |
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Hubble's Sharpest View Of Ma
| title |
Hubble's Sharpest View Of Mars |
| Description |
The sharpest view of Mars ever taken from Earth was obtained by the recently refurbished NASA Hubble Space Telescope (HST). This stunning portrait was taken with the HST Wide Field Planetary Camera- 2 (WFPC2) on March 10, 1997, just before Mars opposition, when the red planet made one of its closest passes to the Earth (about 60 million miles or 100 million km). At this distance, a single picture element (pixel) in WFPC2's Planetary Camera spans 13 miles (22 km) on the Martian surface. The Martian north pole is at the top (near the center of the bright polar cap) and East is to the right. The center of the disk is at about 23 degrees north latitude, and the central longitude is near 305 degrees. This view of Mars was taken on the last day of Martian spring in the northern hemisphere (just before summer solstice). It clearly shows familiar bright and dark markings known to astronomers for more than a century. The annual north polar carbon dioxide frost (dry ice) cap is rapidly sublimating (evaporating from solid to gas), revealing the much smaller permanent water ice cap, along with a few nearby detached regions of surface frost. The receding polar cap also reveals the dark, circular sea' of sand dunes that surrounds the north pole (Olympia Planitia). Other prominent features in this hemisphere include Syrtis Major Planitia, the large dark feature seen just below the center of the disk. The giant impact basin Hellas (near the bottom of the disk) is shrouded in bright water ice clouds. Water ice clouds also cover several great volcanos in the Elysium region near the eastern edge of the planet (right). A diffuse water ice haze covers much of the Martian equatorial region as well. The WFPC2 was used to monitor dust storm activity to support the Mars Pathfinder and Mars Global Surveyor Orbiter Missions, which are currently en route to Mars. Airborne dust is most easily seen in WFPC2's red and near-infrared images. Hubble's "weather report" from these images in invaluable for Mars Pathfinder, which is scheduled for a July 4 landing. Fortunately, these images show no evidence for large-scale dust storm activity, which plagued a previous Mars mission in the early 1970s. The WFPC2 was used to observe Mars in nine different colors spanning the ultraviolet to the near infrared. The specific colors were chosen to clearly discriminate between airborne dust, ice clouds, and prominent Martian surface features. This picture was created by combining images taken in blue (433 nm), green (554 nm), and red (763 nm) colored filters. This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page [ http://oposite.stsci.edu/pubinfo/ ] at http://oposite.stsci.edu/pubinfo/ Photo Credit: David Crisp and the WFPC2 Science Team (Jet Propulsion Laboratory/California Institute of Technology) |
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Springtime North Polar Dust
| title |
Springtime North Polar Dust Storms |
| Description |
As on the Earth, many severe storms brew in the martian polar regions. Here, temperature contrasts between the cold carbon dioxide ("dry ice") seasonal frost cap and the warm ground adjacent to it--combined with a flow of cool polar air evaporating off the cap--sweeps up dust and funnels it into swirling dust storms along the cap edge. The dust storms shown here were observed during the recent northern spring by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) in May 2002. The picture is a mosaic of daily global images from the MOC wide angle cameras. The north polar cap is the bright, frosty surface at the top. Images Credit: NASA/JPL/Malin Space Science Systems Caption by: K. S. Edgett and M. C. Malin, MSSS |
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Mars and Earth Dust Storms
| title |
Mars and Earth Dust Storms |
| Description |
seasonal meteorology [ http://www.thirdworld.org/role.html ] and the health of biological communities [ http://catbert.er.usgs.gov/african_dust/ ]. Photo Credit: NASA/JPL/Malin Space Science Systems, Spring on Mars...in either hemisphere...is a time for local and regional dust storms. These storms arise as the seasonal carbon dioxide frost cap, which can extend almost half-way to the equator, sublimes in the warming spring environment. Several factors promote these dust storms: * the atmospheric pressure is increasing as carbon dioxide frost (CO2) sublimes--higher pressure allows more dust to be suspended, and for a longer time, * the temperature contrast between the frost covered surface and immediately adjacent, recently defrosted surfaces is quite high, creating thermally-generated winds that circulate onto and off of the frost cap edge, * similar, temperature-driven winds arise as sublimation of frost covering sun-facing slopes and dark sandy surfaces deep within the polar region creates intense slope winds away from the higher-standing layered deposits and permanent cap. The roughly circular, polar orbit of the Mars Global Surveyor (MGS) spacecraft affords a view not unlike that seen by low Earth-orbiting environmental satellites. Mars is roughly 6800 km (4226 mi) in diameter, and a 370 km (230 mi) average altitude gives a diameter to altitude ratio for MGS of 18.4:1. For comparison, the SeaStar spacecraft in Earth orbit follows a very similar orbit: it's the diameter to altitude ratio is 17.5:1 (12,760 km or 7,928 mi diameter relative to a 705 km or 438 mi altitude). Each spacecraft covers the entire planet in 12 orbits. In this figure, we compare a recent dust storm on Mars with one that occurred earlier this year on Earth. The top image shows a martian north polar dust storm observed on 29 August 2000. This image is part of the Mars Orbiter Camera (MOC) daily global map--a low resolution, two-color view of Mars acquired from pole to pole every orbit. The storm is moving as a front, outward from a central "jet," and marginal "vortices" can be seen. In this image it extends about 900 km (560 mi) out from the north polar seasonal frost cap. The region on the right side of the Mars picture includes the north pole. The bottom image shows a terrestrial dust storm, seen in a SeaWiFS image [ http://seawifs.gsfc.nasa.gov/SEAWIFS/IMAGES/SEAWIFS_GALLERY.html ], acquired on 26 February 2000. This storm extends about 1800 km (1100 mi) off the coast of northwest Africa near the Earth's equator. Both images are shown at the same scale, 4 km (2.5 mi) per pixel. Dust storms play an important role in governing the climate of Mars. The rare, global storms alter the planet's total heat balance and promote variations in seasonal frost formation and dissipation, and greatly affect the distribution of water vapor. Local and regional storms, especially those in the polar regions, affect the rate at which seasonal frost evolves, and control local and regional weather patterns. On Earth, dust storms are also being recognized as contributing to environmental change, potentially influencing |
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A Mid-Summer's Dust Devil
| title |
A Mid-Summer's Dust Devil |
| Description |
One objective for the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) in the Extended Mission is to continue looking for changes and dynamic events taking place on the red planet. The feature shown here elicited gasps of exitement among the MOC Operations Staff when it was received in early April 2001. The feature is a dust devil. Dust devils are spinning, columnar vortices of wind that move across the landscape, pick up dust, and look somewhat like miniature tornadoes. Dust devils are a common occurrence in dry and desert landscapes on Earth as well as Mars. When this dust devil was spied in Amazonis Planitia on April 10th, the MOC was looking straight down. Usually when the camera is looking down the dust devil will appear as a circular, fuzzy patch with a straight shadow indicating its columnar shape. In this case, however, the dust devil is somewhat curved and kinked---its shape is best seen in the shadow it casts to the right. A thin, light-toned track has been left by the dust devil as it moved eastward across the landscape. Usually, such tracks are darker than the surroundings, in this case the light tone might indicate that the dust being removed by the passing dust devil is darker than the surface underneath the thin veneer of dust. Dust devils most typically form when the ground heats up during the day, warming the air immediately above the surface. As the warmed air nearest the surface begins to rise, it spins. The spinning column begins to move across the surface and picks up loose dust (if any is present). The dust makes the vortex visible and gives it the "dust devil" or tornado-like appearance. This dust devil occurred at an optimal time for dust devils whether on Earth or Mars---around 2 p.m. local time in the middle of Northern Hemisphere Summer. North is up, sunlight illuminates the scene from the left (west), and 500 meters is about 547 yards. The shadow cast by the dust devil goes off the edge of the image, but the length shown here (about 1.5 km) indicates that the dust devil was a bit more than 1 km (0.62 mi) in height. Images Credit: NASA/JPL/Malin Space Science Systems |
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Mid-Winter Dust Storms Near
| title |
Mid-Winter Dust Storms Near Hellas Planitia |
| Description |
One of the primary objectives for the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) during the Extended Mission is to continue daily monitoring of martian weather as expressed in clouds, dust storms, and patches of polar frost. During the Primary Mission, which lasted from March 1999 through January 2001, changes that occurred over a single martian year (687 Earth days) were observed. Now it is possible to see what the martian atmosphere will do for at least two-thirds of a second martian year, because the Extended Mission will run into April 2002. This picture captures two dust storms, each large enough to cover Arizona or New Mexico. One is located near the lower left, the other at the lower right. Taken on April 8, 2001 (mid-southern winter), this is a mosaic of six MOC daily global images centered around Hellas Planitia in the martian southern hemisphere. Hellas Planitia is the dominant elliptical feature just below the center of the picture. The bright, nearly white surfaces along the lower (southern) edge of the picture are covered by wintertime frost. The strong temperature difference between the winter frost and the warmer air just off the edge of this polar cap generates winds that---at this time of year---are often strong enough to lift dust into large, reddish-brown, billowy clouds. North is up and sunlight illuminates the area from the upper left. The martian equator forms the arc along the top of the picture, 500 kilometers (km) is equal to about 311 miles. The approximately 500 kilometer-wide circular feature just above the center is the crater Huygens. Image Credit: NASA/JPL/Malin Space Science Systems |
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Mars Opposition and Equinox
| title |
Mars Opposition and Equinox |
| Description |
Prior to the Mariner 4 flyby in 1965, all we knew about Mars came from Earth-based telescopic observations. At best, Mars is a challenging object to observe, due to its small size, low contrast, and turbulence in Earth's atmosphere. The best times to see the planet are around its closest approaches to Earth, which occur near "opposition", when the two planets are roughly in a line on one side of the Sun. This occurs about every 26 months, when Mars can appear to grow (in the night sky) to as large as about 20 arc-seconds in size. (20 arc-seconds is about the apparent size of a dime seen from 190 meters, or about the length of two football fields, away, it is about the size of a crater 40 kilometers (25 miles) in diameter on the Moon.) In 2001, Mars is at opposition on June 13-14 and makes its closest approach to Earth on June 21, when it is about 67 million kilometers (~42 million miles) away and subtends 20.8 arc-seconds in the sky. For observers in the northern hemisphere, it can be seen as a bright (magnitude -2) red object, low in the southern sky near the constellation Scorpius, in the evening. Southern hemisphere observers have a better view, as Mars is higher in the sky from that vantage. (See http://www.skypub.com/ [ http://www.skypub.com/ ] for more information.) Not only is Mars at opposition June 13-14, 2001, and making its closest approach to Earth since 1988 on June 21st, on June 17-18 Mars will be at equinox, with the southern hemisphere turning to spring and the nothern hemisphere begins autumn. The diagrams below illustrate the opposition and equinox configurations of Mars. The Image above is one of a series of simulated views of Mars as it would be seen from the Mars Global Surveyor space craft. To view the rest of these images please go to the June 2001: Mars Opposition and Equinox page at the Malin Space Science Systems [ http://www.msss.com/mars_images/moc/opposition_6_2001/index.html ] web site. Mars Animation Animation of simulated Earth-based views of Mars. Photo Credit: NASA/JPL/Malin Space Science Systems |
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Changes Over a Martian Year
| title |
Changes Over a Martian Year -- New Dark Slope Streaks in Lycus Sucli |
| Description |
Now in its Extended Mission, Mars Global Surveyor (MGS) is into its second Mars year of systematic observations of the red planet. With the Extended Mission slated to run through April 2002, the Mars Orbiter Camera (MOC) is being used, among other things, to look for changes that have occurred in the past martian year. Because Mars is farther from the Sun than Earth, its year is longer---about 687 Earth days. The two pictures shown here cover the same portion of Lycus Sulci, a rugged, ridged terrain north of the giant Olympus Mons volcano. The interval between the pictures span 92% of a martian year (August 2, 1999 to April 27, 2001). Dark streaks considered to result from the avalanching of dry, fine, bright dust are seen in both images. The disruption of the surface by the avalanching materials is thought to cause them to appear darker than their surroundings, just as the 1997 bouncing of Mars Pathfinder's airbags and the tire tracks made by the Sojourner rover left darkened markings indicating where the martian soil had been disrupted and disturbed. The arrows in the April 2001 picture indicate eight new streaks that formed on these slopes in Lycus Sulci since August 1999. These observations suggest that a new streak forms approximately once per martian year per kilometer (about 0.62 miles) along a slope. In both images, north is toward the top/upper right and sunlight illuminates each from the left. Dark (as well bright) slope streaks are most common in the dust-covered martian regions of Tharsis, Arabia, and Elysium. Additional examples of dark slope streaks can be seen in the following earlier MOC image media releases: * "Recent Movements: New Landslides in Less than 1 Martian Year," March 12, 2000 [ http://www.msss.com/mars_images/moc/lpsc2000/3_00_massmovement/ ] * "Dark Slope Streaks on Elysium Basin Buttes," July 19, 1999 [ http://www.msss.com/mars_images/moc/7_19_99_fifthMars/18_slopes/ ] Images Credit: NASA/JPL/Malin Space Science Systems |
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Mars Express Seen by Mars Gl
| title |
Mars Express Seen by Mars Global Surveyor, This picture shows the Mars Express orbiter as a white, wavy, slanted streak centered against a vast, deep black background. The lines of the spacecraft make it appear somewhat like a jagged, three-inch worm in space. |
| Description |
This picture of the European Space Agency's Mars Express spacecraft by the Mars Orbiter Camera on NASA's Mars Global Surveyor is from the first successful imaging of any spacecraft orbiting Mars by another spacecraft orbiting Mars. The picture is a composite of two views of Mars Express that Mars Orbiter Camera acquired on April 20, 2005, from distances of about 250 and 370 kilometers (155 and 229 miles). Owing to the large distance between Mars Global Surveyor and Mars Express when the two views could be acquired and to a substantial cross-track component of apparent motion for which no correction could be made, Mars Express appears in the image as a narrow blur rather than as a well-defined spacecraft. It appears in the image to be about 1.5 meters in the small dimension and 15 meters in the long dimension, which is consistent with the viewing distance, pixel scale, and encounter geometry. The components of Mars Express when viewed from the same angle as this image can be seen in an artist's rendition http://photojournal.jpl.nasa.gov/figures/PIA07944_fig1.jpg and an annotated rendition http://photojournal.jpl.nasa.gov/figures/PIA07944_fig2.jpg of the spacecraft. Mars Express was launched on June 3, 2003, and reached Mars on Dec. 25, 2003. Mars Global Surveyor left Earth on Nov. 7, 1996, and arrived in Mars orbit on Sept. 12, 1997. JPL, a division of the California Institute of Technology, Pasadena, manages Mars Global Surveyor for NASA's Science Mission Directorate, Washingon, D.C. Credit: NASA/JPL/MSSS |
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Happy 8th Birthday, MGS
| title |
Happy 8th Birthday, MGS |
| Description |
. The reason there is no MOC image for April 1999 is a product of the MGS spacecraft's 8-year history at Mars. MGS was certainly in orbit at the time, and it was taking data during the month of April. However, the camera did not obtain any images between 17 and 28 April because the spacecraft encountered, and then had to be recovered from, a problem. It was at this time that the spacecraft team realized that there is something obstructing the full movement of MGS's high gain antenna. A work-around was created and the mission has continued, ever since, but the down-side was that MOC did not have the opportunity in 1999 to provide detailed observations of the north polar, summertime, annular cloud. The remaining three pictures show MGS MOC views of the cloud feature, as it appeared in the subsequent 3 Mars years. Each year, the cloud appeared at about the same time or slightly earlier than in the previous year. Despite its superficial resemblance to a hurricane or cyclone on Earth, the northern summer annular cloud does not rotate. The cloud forms as different currents of air merge in the morning hours in the polar region, by afternoon, the annular cloud typically dissipates or breaks up into smaller clouds. MGS MOC has observed other repeated phenomena over the course of its 8-year mission orbiting Mars. These include dust storms that repeat, year after year, in the same location within a week or two of the time it occurred in the previous year. They also include dust devils in northern Amazonis, which start up shortly after the first day of spring, and keep occurring nearly every afternoon until a few days into the autumn season. MOC is continuing its mission to monitor the planet -- in 2006, MOC's weather observations will be used to provide guidance for the aerobraking maneuvers of the Mars Reconnaissance Orbiter (MRO). MOC images will show whether dust storms are occurring, and whether the dust suspended by these storms will impact the density of the atmosphere at the altitudes that MRO is passing through to slow the spacecraft and change its orbit to the one desired for the MRO primary mission. Location Near: 90°N Season: Northern Summer Credit: NASA/JPL/MSSS, Mars Global Surveyor (MGS) entered Mars orbit on 12 September 1997. Today, we celebrate the MGS's 8th anniversary! The 8 Earth years that MGS has been in orbit span portions of 5 martian years. One of the critical science activities that the Mars Orbiter Camera (MOC) has been engaged in for the past 8 years has been to document daily changes in the martian weather. Each day that MOC is operating, the red and blue wide angle cameras are used to build up a daily global map. These maps provide a record of the planet's changing meteorological conditions. One of the most exciting observations that the MOC wide angle cameras have made during these 8 years is that the red planet has very repeatable weather patterns. In light of weather-related problems and disruptions that occur every year on Earth, one can only imagine how nice it would be if our planet followed a similar, repeated pattern. The four pictures shown here provide an example of one of the weather phenomena that repeat each martian year. Each picture shows the north polar region of Mars during the northern summer season. Each picture is a composite of several images acquired at different visible wavelengths to give a color view of the planet. Each picture was taken about 1 Mars year apart, and each shows an annular (circular) cloud located over the same terrain each summer. The first picture, acquired in April 1999, is actually not from the MGS MOC instrument. It was obtained by the Hubble Space Telescope (HST) Wide Field Planetary Camera 2 (WFPC2) and was originally released by the Space Telescope Science Institute on 19 May 1999 [ http://hubblesite.org/newscenter/newsdesk/archive/releases/1999/22/ ] |
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Spirit Rover on 'Husband Hil
| title |
Spirit Rover on 'Husband Hill' |
| Description |
Two Earth years ago, NASA's Mars Exploration Rover Spirit touched down in Gusev Crater. The rover marked its first Mars-year (687 Earth days) anniversary in November 2005. Shortly before Spirit's Martian anniversary, the Mars Orbiter Camera on NASA's Mars Global Surveyor acquired an image covering approximately 3 kilometers by 3 kilometers (1.9 miles by 1.9 miles) centered on the rover's location at that time in the "Columbia Hills.""Husband Hill," the tallest in the range, is just below the center of the image. The image has a resolution of about 50 centimeters (1.6 feet) per pixel. North is up, illumination is from the left. The location is near 14.8 degrees south latitude, 184.6 degrees west longitude. The image was acquired on Nov. 2, 2005. A white box indicates the location of an excerpted portion on which the location of Spirit on that date is marked. Dr. Timothy J. Parker of the Mars Exploration Rover team at the NASA's Jet Propulsion Laboratory, Pasadena, Calif., confirmed the location of the rover in the image. The region toward the bottom of the image shows the area where the rover is currently headed. The large dark patch and other similar dark patches are accumulations of windblown sand and granules. Credit: NASA/JPL-Caltech/MSSS |
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Rolling Stones Make New Boul
| title |
Rolling Stones Make New Boulder Tracks |
| Description |
When a boulder rolls down a dusty slope, it can leave behind a trail of depressions. Usually known as boulder tracks, these features have been documented and studied on Earth, the Moon, and Mars. Geologists studying the Moon and Mars can use these tracks to learn about the physical properties of the fine-grained debris encountered by the boulder as it rolled down the slope. Because of the high-resolution capability (0.5 to 12 meters, 1.6 to 39 feet, per pixel) of the Mars Orbiter Camera on NASA's Mars Global Surveyor spacecraft, dozens of boulder track sites have been identified on the red planet. A Mars Orbiter Camera image of one set of boulder tracks in a south mid-latitude crater (located near 35.8 degrees south latitude, 158.4 degrees west longitude) was obtained on Nov. 14, 2003, (left). A second image of the same site, from Dec. 4, 2004, (right) shows that more than a dozen new boulder tracks formed on the crater wall during the intervening time. Mars is an active planet, with geologic changes occurring -- at some scale -- every day. In this case, some time between mid November 2003 and early December 2004, a suite of boulders became dislodged from the crater wall, then rolled and perhaps bounced their way to the crater floor. Wider context for the site can be seen in a mosaic of Mars Orbiter Camera wide-angle images acquired in May 1999 (insert MOC2-1213a). The white box indicates the location of the later, higher-resolution views. Why the new boulders slid down the slope is unknown. This is the product of a mass movement (landsliding) process. That is, gravity is the main culprit. Whether the boulder motion was triggered by something -- a seismic event ("Marsquake") or strong winds -- is not known. Also unknown is whether all of the new boulder tracks formed at the same time, in response to a single event, or rolled downhill one at a time over the nearly 13-month period. The Mars Orbiter Camera was built and is operated by Malin Space Science Systems, San Diego, Calif. Mars Global Surveyor left Earth on Nov. 7, 1996, and began orbiting Mars on Sept. 12, 1997. JPL, a division of the California Institute of Technology, Pasadena, manages Mars Global Surveyor for NASA's Science Mission Directorate, Washington. Credit: NASA/JPL/MSSS |
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Scarp at Head of Chasma Bore
| title |
Scarp at Head of Chasma Boreale |
| Description |
This view shows sharp detail of a scarp at the head of Chasma Boreale, a large trough cut by erosion into the martian north polar cap and the layered material beneath the ice cap. The picture is a mosaic of two images acquired in January 2005 by the Mars Orbiter Camera on NASA's Mars Global Surveyor, using a resolution-enhancing technique called "compensated pitch and roll targeted observation." The camera team considers this the best pair of images yet acquired using that technique. During each northern summer on Mars, there occurs a narrow window in time of two to three months when conditions are ideal to image the north polar cap at high resolution. Throughout this period, the atmosphere is generally clear over the cap, and the seasonal carbon-dioxide frost from the previous winter and spring has sublimed away, permitting a good view of the surface geology. The two images in this mosaic were acquired during this brief period during the most recent northern summer. Within a few weeks of when these images were acquired, dust storm activity picked up in the north polar region, making the atmosphere too dusty to obtain any more detailed views until late 2006. Chasma Boreale is cut into the layered material that lies beneath the water ice of the north polar cap. For decades, these layered materials were assumed to consist of a mixture of ice and dust. Mars Orbiter Camera images obtained in 1999 and 2001 began to show that some of the layers are a source for windblown sand. The science objective for the two images shown in this mosaic was to look for boulders in the debris shed from the steep slopes cut into the north polar layers by Chasma Boreale. Finding boulders would imply that the layers that are the most resistant to erosion in the polar region are as competent as solid rock, perhaps giving a new insight into the nature of the polar layered materials. The pictured site is near 84.8 degrees north latitude, 356.4 degrees west longitude. Examination of the high-resolution mosaic shows that there are indeed some large boulders that have eroded out of the layered materials and rolled down the slopes. It is possible, therefore, that the north polar layers are not simply a mixture of ice, dust, and sand. Some layers may actually be rock, cemented by minerals rather than by ice. Alternatively, if the materials are cemented by ice, then a future high-resolution view might show that the boulders have become smaller over time. In addition to the observation of boulders eroding out of the polar layered materials, the mosaic also helps confirm that dark sand is eroding out of the polar layered materials, and that there are three different groups of layers under the polar ice. The upper unit is light-toned, finely layered, and more resistant to erosion (more competent, less easily destroyed by erosion) than the middle unit, which is rich in dark sand but also has several shelf-forming layers in it. Finally, below the dark, sandy layer is a third unit, that is light-toned and has a different appearance relative to the other two units. Some of its layers have surfaces that have been broken by shallow fractures into polygonal and linear forms, also implying that they are hard, resistant rock. The level of detail seen in the mosaic was made possible by the development of a resolution-enhancing technique for using the Mars Orbiter Camera. During 2003 and 2004, the Mars Orbiter Camera operations team at Malin Space Science Systems, San Diego, Calif., worked closely with the Mars Global Surveyor operations teams at the Jet Propulsion Laboratory, Pasadena, Calif., and Lockheed Martin Space Systems, Denver, Colo., to develop a new technique in which the spacecraft does a maneuver that permits the camera to acquire images at a higher spatial resolution than normal. Usually, Mars Orbiter Camera images have a resolution of about 1.5 meters (5 feet) per pixel, and the camera can be commanded to acquire lower resolution data when desired. To obtain a higher resolution, the whole spacecraft must be pitched at such a rate that the camera over-samples its view of the martian surface in the down-track direction. Called compensated pitch and roll targeted observation, or cPROTO, this technique allows Mars Orbiter Camera to obtain images that have a resolution of about 50 centimeters (20 inches) per pixel in the down-track direction, and 150 centimeters (5 feet) per pixel in the cross-track dimension. The Mars Orbiter Camera was built and is operated by Malin Space Science Systems, San Diego, Calif. Mars Global Surveyor left Earth on Nov. 7, 1996, and began orbiting Mars on Sept. 12, 1997. JPL, a division of the California Institute of Technology, Pasadena, manages Mars Global Surveyor for NASA's Science Mission Directorate, Washington Credit: NASA/JPL/MSSS |
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Eberswalde Delta in High Res
| title |
Eberswalde Delta in High Resolution |
| Description |
Scientifically, perhaps the most important result from use of the Mars Orbiter Camera on NASA's Mars Global Surveyor during that spacecraft's extended mission has been the discovery and documentation of a fossil delta. The feature is located in a crater northeast of Holden Crater, near 24.0 degrees south latitude, 33.7 degrees west longitude. Since the announcement of the discovery of the delta in November 2003, the International Astronomical Union has provided a provisional name (pending final approval) for the crater in which the landforms occur. The crater has been named Eberswalde, for a town in Germany. This image offers a higher-resolution view of a portion of the fossil delta than any seen earlier. North is up. At the bottom of the frame, the image includes the north end of a looping, inverted, meandering channel. The image covers an area of about 3 by 3 kilometers (1.9 x 1.9 miles). It was produced using a technique called "compensated pitch and roll targeted observation," in which the rotation rate of the spacecraft is adjusted to match the ground speed under the camera. At full resolution, this map-projected image is at 50 centimeters (20 inches) per pixel. Additional images from Mars Orbiter Camera provide some context and show a nearby portion of the fossil delta's inverted channels at a spatial scale of 1.5 meters (about 5 feet) per pixel. The relative positions of these three images are indicated in a mosaic image of the entire delta, for which the unmarked version was released in November 2003. The first Mars Orbiter Camera narrow angle images of some of the landforms in the delta were acquired in 2000, during the Mars Global Surveyor primary mission, but those pictures did not show very well the unambiguous inverted channel forms. Not until the second Earth year of the orbiter's extended mission were the deltaic features recognized in Mars Orbiter Camera images obtained in March and June of 2002. Following the initial observations in 2002, the Mars Orbiter Camera team began a systematic effort to map the entire Eberswalde Crater delta. Most of this imaging required slewing the whole spacecraft in a technique called "roll only targeted observation" so that it pointed the camera toward the feature. In this way, the camera team was able to build up a mosaic of the delta much more quickly than would have been the case if the team had simply relied upon chance crossing of the delta by the orbiter's usual ground track. This technique was not employed during Mars Global Surveyor's primary mission, except in the search for Mars Polar Lander, but became a routine part of the tool kit during the extended mission. Even with the "roll only targeted observation" technique, it took more than one Earth year to build up a complete mosaic of images of the delta. In the meantime, the first data showing the deltaic landforms were archived and released to the public and scientific community, long before the Mars Orbiter Camera team's, analysis and mosaic were complete. Some scientists began independent analyses of the landform at that time. The initial analysis and announcement of the feature was finally published in November 2003. The Eberswalde delta provides the first clear, "smoking gun" evidence that some valleys on Mars experienced persistent flow of a liquid with the physical properties of water over an extended period of time, as do rivers on Earth. In addition, because the delta today is lithified -- that is, hardened to form rock -- it provided the first unambiguous evidence that some martian sedimentary rocks were deposited in a liquid (presumably, water) environment. The presence of meandering channels, a cut-off meander, and crisscrossing channels at different elevations (one above the other), provided the clear geologic evidence for these interpretations. After the sediments were deposited to form the delta, the material was further buried by other materials -- probably sediments -- that are no longer present. The entire package of buried material became cemented and hardened to form rock. Later, erosive processes such as wind stripped away the overlying rock, re-exposing the delta. Now preserved essentially as a fossil, the former floors of channels in the delta became inverted, to form ridges, by erosion. Channels can be inverted by erosion on both Earth and Mars. Usually this happens when the channel floor, or the material filling the channel, is harder to erode than the surrounding material into which the channel was cut. In some cases, the channels on Earth and Mars have been filled by lava to make them more resistant to erosion. In the case of Eberswalde, there are no lava flows, instead, the channel floors may have been rendered resistant to erosion either by being better-cemented than the surrounding material, or composed of coarser-grained sediment (such as sand and gravel as opposed to silt), or both. The Mars Orbiter Camera was built and is operated by Malin Space Science Systems, San Diego, Calif. Mars Global Surveyor left Earth on Nov. 7, 1996, and began orbiting Mars on Sept. 12, 1997. JPL, a division of the California Institute of Technology, Pasadena, manages Mars Global Surveyor for NASA's Science Mission Directorate, Washington. Credit: NASA/JPL/MSSS |
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Recently-Formed Impact Crate
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Recently-Formed Impact Crater |
| Description |
Scientists using the Mars Orbiter Camera on NASA's Mars Global Surveyor spacecraft have discovered a crater that appears to have formed on Mars in the past 20 or so Earth years, and have used it and several other similar craters to estimate the present cratering rate on Mars. One of the basic tenets of planetary geology is that impact craters have accumulated on planetary surfaces at roughly a constant rate since the early history of the solar system. This appears to have been the case for small craters on the surface of the Moon, as shown by measurements of the length of time that lunar rocks created by small impacts have been exposed to cosmic rays, as determined by laboratory measurements of samples returned to Earth by the Apollo astronauts. This principle should permit the number of craters found on a planetary surface to be used to determine the age of that surface, if the rate at which new craters form is known. Scientists have previously estimated the cratering rate of Mars by scaling the lunar cratering rate based on the proximity of Mars to the asteroid belt, and by performing calculations based on orbital mechanics. Another way to establish the cratering rate of Mars would be to use long-term observations, say, from orbiting spacecraft, to actually locate new craters. The new crater is located on the southern rim of the summit crater, or caldera, of the intermediate-sized martian volcano, Ulysses Patera. The site was imaged by the Viking 2 orbiter in 1976 (left, an enlarged portion of the image) and in narrow-angle views by the Mars Orbiter Camera in 1999 (center) and 2005 (right). The new crater, about 25 meters (82 feet) across, is marked by a distinct dark, rayed pattern of ejected material, or ejecta, which is seen to have faded somewhat between 1999 and 2005. Ulysses Patera, a volcanic shield about 100 kilometers (62 miles) in diameter volcanic shield, located near 2.5 degrees north latitude, 121.3 degrees west longitude, is one of the Tharsis volcanoes and is partly buried by younger lava flows. The summit caldera is about 55 kilometers (34 miles) in diameter. The amount that the crater's rays faded between 1999 and 2005 can be used to help estimate how many years ago the crater formed. The actual contrast between the ejecta and the undisturbed volcano summit materials is actually much less than it appears to be in these processed images, and the amount of fading is also much less. Images of disturbed surfaces from various parts of Mars, such as dust devil tracks, dark slope streaks and rover tracks, indicate that disturbed surfaces on Mars are dark and that they lighten with time. Using these other examples to estimate how dark the ejecta from the Ulysses crater was originally, and how much it has faded in six years, suggests the crater formed in the early to mid 1980s. The rate at which dark surfaces lighten on Mars is not uniform over the whole planet, but scientists using the Mars Orbiter Camera have found a number, of other craters with dark ejecta that have faded during the Mars Global Surveyor mission. The scientists estimate that these craters probably formed within the past 100 years. Although the sample is very small (the Mars Orbiter Camera narrow angle camera has imaged barely 4 percent of Mars), it appears that the recent cratering rate for craters on Mars 25 to 100 meters (82 to 328 feet) in diameter is about 0.000000003 to 0.000000006 craters per square kilometer (0.39 square mile) per Earth year, which is about five times lower than previous estimates. The site of the new crater is shown in wider context in a comparison of the 1976 Viking image with wide-angle views taken by the Mars Orbiter Camera in 1999 and 2005 (insert MOC2-1214b), and in even wider context in a regional mosaic of Viking images (insert MOC2-1214c). The Mars Orbiter Camera was built and is operated by Malin Space Science Systems, San Diego, Calif. Mars Global Surveyor left Earth on Nov. 7, 1996, and began orbiting Mars on Sept. 12, 1997. JPL, a division of the California Institute of Technology, Pasadena, manages Mars Global Surveyor for NASA's Science Mission Directorate, Washington. Credit: NASA/JPL/MSSS/USGS |
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Four Mars Years of South Pol
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Four Mars Years of South Polar Changes |
| Description |
One of the most profound discoveries that would not have been possible if NASA's Mars Global Surveyor mission had not been extended beyond its primary mission of one Mars year (687 Earth days) is that of dramatic changes that take place in the south polar residual ice cap each martian year. To make this discovery, the Mars Orbiter Camera on the spacecraft had to be employed during a second Mars year to repeat images of sites on the south polar cap that had been imaged during the primary mission. The initial discovery was made in 2001, when the camera team repeated images of portions of the south polar cap that had already been imaged in 1999. The goal of these images was to obtain stereo views, which would allow investigators to see the topography of the cap in three dimensions and to measure the thickness of the polar ice layers. It was not possible to produce the desired 3-D views. To the team's surprise, the landforms of the south polar cap had changed. The south polar residual cap -- that is, the portion of the ice cap that remains bright and retains ice throughout the southern summer season -- was seen in 1997 and 1999 images to have a complex terrain of broad, relatively flat mesas, small buttes, and many pits and troughs. Pits are generally circular and in some areas visually resemble a stack of thin slices of Swiss cheese. Very early in the Mars Global Surveyor mission, the Mars Orbiter Camera team speculated that these landforms must be carved into frozen carbon dioxide, because they look so unfamiliar and because Viking orbiter infrared measurements indicated that the south polar cap is cold enough consist of frozen carbon dioxide, even in summer. The observations made by Mars Orbiter Camera in 2001, during the first part of the extended mission, showed that the scarps and pit walls of the south polar cap had retreated at an average rate of about 3 meters (10 feet) since 1999. In other words, they were retreating 3 meters per Mars year (and, of course, most of that retreat takes place during the summer). In some places on the cap, the scarps retreat less than 3 meters a Mars year, and in others it can retreat as much as 8 meters (26 feet) per martian year. Of the two volatile materials one is likely to find in a frozen state on Mars -- water and carbon dioxide -- it is carbon dioxide that is volatile enough to permit scarp retreat rates like those observed by the Mars Orbiter Camera. Over time, south polar pits merge to become plains, mesas turn into buttes, and buttes vanish forever. Since 2001, two additional Mars years have elapsed. A scientific benefit of having a long extended mission for Mars Global Surveyor has been the opportunity to document how the polar cap is changing each year. Four images are shown here, plus an animation at left presenting the four frames in sequence. The location is near 86.3 degrees south latitude, 49.4 degrees west longitude, and the images show the same portion of the south polar residual, cap as it appeared in 1999, 2001, 2003, and 2005. Comparing the images or viewing the animation makes it evident that the landscape of the south polar cap has been changing rapidly over the past four martian years. Each year that Mars Global Surveyor has been in orbit, the landforms of the south polar residual cap have gotten smaller, and the carbon dioxide removed from the cap has not been re-deposited. The implication is that Mars presently has a warm (and possibly warming) climate, with new carbon dioxide going into the atmosphere every year. The other implication is that, at some time in the not-too-distant past, the planet had a colder climate, so that the layers of carbon dioxide could be deposited in the first place. If one takes the rate of scarp retreat and projects it backwards to fill in all of the pits and troughs with the carbon dioxide that has been removed from them, one finds that the colder climate might only have occurred a few centuries to a few tens of thousands of years ago. This kind of time scale is not unlike that of the climate changes that have been recorded on Earth, including the Ice Ages and the smaller fluctuations that have occurred since the last Ice Age (e.g., the "Little Ice Age" of the mid-14th through mid-19th centuries). After the discovery that the pits were enlarging and that we were not seeing carbon-dioxide deposition, it was suggested that interannual variations might be large enough to permit such deposition on a short timescale. However, two Mars years of additional observations show no large magnitude annual differences. Variations that would permit carbon dioxide deposition may require decades. And to see such variations may require many more Mars years of observations by orbiting spacecraft. The Mars Orbiter Camera was built and is operated by Malin Space Science Systems, San Diego, Calif. Mars Global Surveyor left Earth on Nov. 7, 1996, and began orbiting Mars on Sept. 12, 1997. JPL, a division of the California Institute of Technology, Pasadena, manages Mars Global Surveyor for NASA's Science Mission Directorate, Washington. Credit: NASA/JPL/MSSS |
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Southern Hemisphere Polygona
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Southern Hemisphere Polygonal Patterned Ground |
| Description |
On Earth, "periglacial" is a term that refers to regions and processes where cold climate contributes to the evolution of landforms and landscapes. Common in periglacial environments on Earth, such as the arctic of northern Canada, Siberia, and Alaska, is a phenomenon called "patterned ground". The "patterns" in "patterned ground" often take the form of large polygons, each bounded by either troughs or ridges made up of rock particles different in size from those seen in the interior of the polygon. On Earth, many polygons in periglacial environments are directly linked to water: they typically form from stresses induced by repeated freezing and thawing of water, contraction from stress induced by changing temperatures, and sorting of rocks brought to the surface along polygon boundaries by the freeze-thaw processes. Although not exclusively formed by freezing and thawing of water, that is often the dominant mechanism on Earth. Polygons similar to those found in Earth's arctic and antarctic regions are also found in the polar regions of Mars. Typically, they occur on crater floors, or on intercrater plains, between about 60° and 80° latitude. The polygons are best seen when bright frost or dark sand has been trapped in the troughs that form the polygon boundaries. Three examples of martian polygons seen by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) are shown here. Each is located in the southern hemisphere: (a) Polygon troughs highlighted by frost as the south polar cap retreats during spring. The circular features are the locations of buried craters that were originally formed by meteor impact. This image, E09-00029, is located at 75.1°S, 331.3°W, and was acquired on 1 October 2001. (b) Summertime view of polygons, highlighted by dark, windblown sand, on the floor of a crater at 71.2°S, 282.6°W. The image, E12-02319, was obtained on 21 January 2002. (c) Polygon troughs highlighted by the retreating south polar frost cap during southern summer near 80.7°S, 70.4°W. This picture, M11-01795, was taken by MOC on 13 January 2000. Some Mars researchers assume that polygons on the Red Planet are key indictors that ground ice is present or was present in the recent past. However, whether these polygons actually required water ice to form is, in fact, unknown, since dry processes are also known on Earth for form similar polygons. Photo Credit: NASA/JPL/Malin Space Science Systems |
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Spirit's Neighborhood in 'Co
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Spirit's Neighborhood in 'Columbia Hills,' in Stereo |
| Description |
Two Earth years ago, NASA's Mars Exploration Rover Spirit touched down in Gusev Crater. The rover marked its first Mars-year (687 Earth days) anniversary in November 2005. On Nov. 2, 2005, shortly before Spirit's Martian anniversary, the Mars Orbiter Camera on NASA's Mars Global Surveyor acquired an image covering approximately 3 kilometers by 3 kilometers (1.9 miles by 1.9 miles) centered on the rover's location in the "Columbia Hills." The tinted portion of this image gives a stereo, three-dimensional view when observed through 3-D glasses with a red left eye and blue right eye. The tallest peak is "Husband Hill," which was climbed by Spirit during much of 2005. The region south (toward the bottom) of these images shows the area where the rover is currently headed. The large dark patch and other similar dark patches in these images are accumulations of windblown sand and granules. North is up, illumination is from the left. The location is near 14.8 degrees south latitude, 184.6 degrees west longitude. Credit: NASA/JPL-Caltech/MSSS |
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Repeated Clouds over Arsia M
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Repeated Clouds over Arsia Mons |
| Description |
Three wide angle views taken by the Mars Orbiter Camera on NASA's Mars Global Surveyor at intervals approximately one Mars year apart show similar spiral dust clouds over a volcano named Arsia Mons. The upper-left image was taken on June 19, 2001, the first day of southern winter on Mars. The upper-right image was taken on April 24, 2003, in late southern autumn on Mars. The lower image was taken on Feb. 25, 2005, slightly earlier in late southern autumn on Mars. Some parts of Mars experience weather phenomena that repeat each year at about the same time. In some regions, the repeated event may be a dust storm that appears every year, like clockwork, in such a way that we can only wish the weather were so predictable on Earth. One of the repeated weather phenomena occurs each year near the start of southern winter over Arsia Mons, which is located near 9 degrees south latitude, 121 degrees west longitude. Just before southern winter begins, sunlight warms the air on the slopes of the volcano. This air rises, bringing small amounts of dust with it. Eventually, the rising air converges over the volcano's caldera, the large, circular depression at its summit. The fine sediment blown up from the volcano's slopes coalesces into a spiraling cloud of dust that is thick enough to actually observe from orbit. The spiral dust cloud over Arsia Mons repeats each year, but observations and computer calculations indicate it can only form during a short period of time each year. Similar spiral clouds have not been seen over the other large Tharsis volcanoes, but other types of clouds have been seen. The spiral dust cloud over Arsia Mons can tower 15 to 30 kilometers (9 to 19 miles) above the volcano. The white and bluish areas in the images are thin clouds of water ice. In the 2005 case, more water ice was present than in the previous years at the time the pictures were obtained. For scale, the caldera of Arsia Mons is about 110 kilometers (68 miles) across, and the summit of the volcano stands about 10 kilometers (6 miles) above its surrounding plains. The Mars Orbiter Camera was built and is operated by Malin Space Science Systems, San Diego, Calif. Mars Global Surveyor left Earth on Nov. 7, 1996, and began orbiting Mars on Sept. 12, 1997. JPL, a division of the California Institute of Technology, Pasadena, manages Mars Global Surveyor for NASA's Science Mission Directorate, Washington. Credit: NASA/JPL/MSSS |
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Spirit on "Husband Hill," wi
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Spirit on "Husband Hill," with 2004 Comparison |
| Description |
Two Earth years ago, NASA's Mars Exploration Rover Spirit touched down in Gusev Crater. The rover marked its first Mars-year (687 Earth days) anniversary in November 2005. On Nov. 2, 2005, shortly before Spirit's Martian anniversary, the Mars Orbiter Camera on NASA's Mars Global Surveyor acquired an image centered on the rover's location in the "Columbia Hills." The location of Spirit on that date is circled on the image on the right. On the left, for comparison, is an image from Jan. 10, 2004, when few dreamed that the Spirit would ever reach the hills from its landing site about three kilometers (two miles) away. The newer image has a resolution of about 50 centimeters (1.6 feet) per pixel. North is up, illumination is from the left. The location is near 14.8 degrees south latitude, 184.6 degrees west longitude. Dr. Timothy J. Parker of the Mars Exploration Rover team at NASA's Jet Propulsion Laboratory, Pasadena, Calif., confirmed the location of the rover in the 2005 image. The scale bar is 50 meters (164 feet). Credit: NASA/JPL-Caltech/MSSS |
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Northern Terra Meridiani Roc
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Northern Terra Meridiani Rocks and Cliffs in 3-D |
| Description |
Extended Mission operations for the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) include opportunities that come up about 10 times a week to turn and point the MGS spacecraft so that MOC can photograph a feature of high scientific interest. Many of these images are targeted to the site of a previous MOC image, so that a stereoscopic ("3-D") view can be obtained. The top picture shows a 115 kilometers (~72 miles) wide portion of northern Terra Meridiani, a region of vast layered rock outcrops similar to portions of southeastern Utah and northern Arizona on Earth. The white box in this context image, located near 2.2°N, 1.3°W, shows the location of the high resolution stereo view obtained by MOC by combining a picture taken March 10, 1999 (FHA-00541) with one obtained by pointing the spacecraft on May 28, 2001 (EO4-02223). The stereo view, which requires red (left-eye) and blue (right-eye) "3-D" glasses to be seen, covers an area approximately 2.3 km (1.4 mi) wide by 6.2 km (3.9 mi) long. The full-resolution view is seen at nearly 1.5 meters (5 ft) per pixel, a scale at which objects the size of airplanes and school buses might be seen. The landscape revealed by the 3-D view is a rugged terrain with steep cliffs and no fresh impact craters. This terrain seems most un-Mars-like compared to the typical cratered and dusty views MOC has provided since it began taking data in September 1997. In fact, one of the MOC science team members remarked, "If I'd seen this landscape used in a movie about Mars five years ago, I'd have said the director had no clue what Mars is supposed to look like." An irregular depression with a flat, mottled, light-toned floor dominates the scene. Small dark ridges on the depression floor near the top center of the image are dunes or drifts formed by wind transport of sandy sediment. The sharp buttes, mesas, and steep cliffs are all indicators that this terrain consists of a broad exposure of martian bedrock. North is up and sunlight illuminates each picture from the left/upper left. Images Credit: NASA/JPL/Malin Space Science Systems |
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