Mission Viking

<h1>PIA00363: Soil Sample Site</h1><div class="PIA00363" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">High-resolution photo of the Martian surface near the Viking Lander 2 shows a few square meters (yards) at one of the possible spots for acquiring a soil sample. The sample will be collected next Saturday (September 11) by the Lander's trenching scoop and delivered to the spacecraft instruments. The rock in the right foreground is about 25 centimeters (10 inches) across. Most rocks appear to have vesicles, or small holes, in them. Such rocks on Earth can be produced by either volcanic processes or by hypervelocity impacts of meteorites. Some areas are lighter than others, suggesting the presence of two kinds of fine-grained materials, which also can be produced by both volcanic and impact processes. A nearby large impact crater, named Mie, may be the source of the rocks and fine-grained material at the landing site.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00363" onclick="window.open(this.href); return false;" title="Voir l'image PIA00363: Soil Sample Site sur le site de la NASA">Voir l'image PIA00363: Soil Sample Site sur le site de la NASA.</a></div>
PIA00363: Soil Sample Site
<h1>PIA00364: Rocky Martian Plain</h1><div class="PIA00364" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">The rocky Martian plain surrounding Viking 2 is seen in high resolution in this 85-degree panorama sweeping from north at the left to east at right during the Martian afternoon on September 5. Large blocks litter the surface. Some are porous, sponge-like rocks like the one at the left edge (size estimate: 1 1/2 to 2 feet); others are dense and fine-grained, such as the very bright rounded block (1 to 1 1/2 feet across) toward lower right. Pebbled surface between the rocks is covered in places by small drifts of very fine material similar to drifts seen at the Viking 1 landing site some 4600 miles to the southwest. The fine-grained material is banked up behind some rocks, but wind tails seen by Viking 1 are not well-developed here. On the right horizon, flat-topped ridges or hills are illuminated by the afternoon sun. Slope of the horizon is due to the 8-degree tilt of the spacecraft.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00364" onclick="window.open(this.href); return false;" title="Voir l'image PIA00364: Rocky Martian Plain sur le site de la NASA">Voir l'image PIA00364: Rocky Martian Plain sur le site de la NASA.</a></div>
PIA00364: Rocky Martian Plain
<h1>PIA00381: First Photograph Taken On Mars Surface</h1><div class="PIA00381" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>This is the first photograph ever taken on the surface of the planet Mars. It was obtained by Viking 1 just minutes after the spacecraft landed successfully early today [July 20, 1976]. The center of the image is about 1.4 meters (five feet) from Viking Lander camera #2. We see both rocks and finely granulated material--sand or dust. Many of the small foreground rocks are flat with angular facets. Several larger rocks exhibit irregular surfaces with pits and the large rock at top left shows intersecting linear cracks. Extending from that rock toward the camera is a vertical linear dark band which may be due to a one-minute partial obscuration of the landscape due to clouds or dust intervening between the sun and the surface. Associated with several of the rocks are apparent signs of wind transport of granular material. The large rock in the center is about 10 centimeters (4 inches) across and shows three rough facets. To its lower right is a rock near a smooth portion of the Martian surface probably composed of very fine-grained material. It is possible that the rock was moved during Viking 1 descent maneuvers, revealing the finer-grained basement substratum; or that the fine-grained material has accumulated adjacent to the rock. There are a number of other furrows and depressions and places with fine-grained material elsewhere in the picture. At right is a portion of footpad #2. Small quantities of fine grained sand and dust are seen at the center of the footpad near the strut and were deposited at landing. The shadow to the left of the footpad clearly exhibits detail, due to scattering of light either from the Martian atmosphere or from the spacecraft, observable because the Martian sky scatters light into shadowed areas.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00381" onclick="window.open(this.href); return false;" title="Voir l'image PIA00381: First Photograph Taken On Mars Surface sur le site de la NASA">Voir l'image PIA00381: First Photograph Taken On Mars Surface sur le site de la NASA.</a></div>
PIA00381: First Photograph Taken On Mars Surface
<h1>PIA00382: First Panoramic View From The Surface Of Mars</h1><div class="PIA00382" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">First panoramic view by Viking 1 from the surface of Mars. (Top): The out-of-focus spacecraft component toward left center is the housing for the Viking sample arm, which is not yet deployed. Parallel lines in the sky are an artifact and are not real features. However, the change of brightness from horizon towards zenith and towards the right (west) is accurately reflected in this picture, taken in late Martian afternoon. At the horizon to the left is a plateau-like prominence much brighter than the foreground material between the rocks. The horizon features are approximately three kilometers (1.8 miles) away. At left is a collection of fine-grained material reminiscent of sand dunes. The dark sinuous markings in left foreground are of unknown origin. Some unidentified shapes can be perceived on the hilly eminence at the horizon towards the right. Patches of bright sand can be discerned among the rocks and boulders in middle distance. In right fore-ground are two peculiarly shaped rocks which may possibly be ventifacts produced by wind abrasion on Mars. A horizontal cloud stratum can be made out halfway from the horizon to the top of the picture. (Bottom): At left is seen the low gain antenna for receipt of commands from the Earth. The projections on or near the horizon may represent the rims distant impact craters. In right foreground are color charts for Lander camera calibration, a mirror for the Viking magnetic properties experiment and part of a grid on the top of the Lander body. At upper right is the high-gain dish antenna for direct communication between landed space-craft and Earth. Toward the right edge is an array of smooth fine-grained material which shows some hint of ripple structure and may be the beginning of a large dune field off to the right of the picture, which joins with dunes seen at the top left in this 300 panoramic view. Some of the rocks appear to be undercut on one side and partially buried by drifting sand on the other.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00382" onclick="window.open(this.href); return false;" title="Voir l'image PIA00382: First Panoramic View From The Surface Of Mars sur le site de la NASA">Voir l'image PIA00382: First Panoramic View From The Surface Of Mars sur le site de la NASA.</a></div>
PIA00382: First Panoramic View From The Surface Of Mars
<h1>PIA00383: First Panoramic View From The Surface Of Mars</h1><div class="PIA00383" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">First panoramic view by Viking 1 from the surface of Mars. The out of focus spacecraft component toward left center is the housing for the Viking sample arm, which is not yet deployed. Parallel lines in the sky are an artifact and are not real features. However, the change of brightness from horizon towards zenith and towards the right (west) is accurately reflected in this picture, taken in late Martian afternoon. At the horizon to the left is a plateau-like prominence much brighter than the foreground material between the rocks. The horizon features are approximately three kilometers (1.8 miles) away. At left is a collection of fine-grained material reminiscent of sand dunes. The dark sinuous markings in left foreground are of unknown origin. Some unidentified shapes can be perceived on the hilly eminence at the horizon towards the right. A horizontal cloud stratum can be made out halfway from the horizon to the top of the picture. At left is seen the low gain antenna for receipt of commands from the Earth. The projections on or near the horizon may represent the rims distant impact craters. In right foreground are color charts for Lander camera calibration, a mirror for the Viking magnetic properties experiment and part of a grid on the top of the Lander body. At upper right is the high gain dish antenna for direct communication between landed spacecraft and Earth. Toward the right edge is an array of smooth fine-grained material which shows some hint of ripple structure and may be the beginning of a large dune field off to the right of the picture, which joins with dunes seen at the top left in this 300ø panoramic view. Some of the rocks appear to be undercut on one side and partially buried by drifting sand on the other.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00383" onclick="window.open(this.href); return false;" title="Voir l'image PIA00383: First Panoramic View From The Surface Of Mars sur le site de la NASA">Voir l'image PIA00383: First Panoramic View From The Surface Of Mars sur le site de la NASA.</a></div>
PIA00383: First Panoramic View From The Surface Of Mars
<h1>PIA00384: Debris Kicked Up By Impact of A Protective Cover from Viking Lander 1</h1><div class="PIA00384" lang="en" style="width:515px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">The patch of dark material toward the top of this picture (arrow) taken by the Viking 1 Lander is the debris kicked up by the impact of a protective cover ejected from the spacecraft at 1 a.m. today. The cylindrical cover, which bounced out of view of the camera, protects the scoop at the end of the soil sampler arm. (The scoop will dig into the Martian surface for the first time on July 28). Dust and debris atop the footpad remains as it was seen in the Lander's first picture taken immediately after landing two days ago. No wind modification is apparent. On the surface, a variety of block sizes, shapes and tones are seen, and some rocks are Partially buried.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00384" onclick="window.open(this.href); return false;" title="Voir l'image PIA00384: Debris Kicked Up By Impact of A Protective Cover from Viking Lander 1 sur le site de la NASA">Voir l'image PIA00384: Debris Kicked Up By Impact of A Protective Cover from Viking Lander 1 sur le site de la NASA.</a></div>
PIA00384: Debris Kicked Up By Impact of A Protective Cover from Viking Lander 1
<h1>PIA00385: High Resolution Image From Viking Lander 1</h1><div class="PIA00385" lang="en" style="width:517px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">Viking 1 took this high-resolution picture today, its third day on Mars. Distance from the camera to the nearfield (bottom) is about 4 meters (13 feet); to the horizon, about 3 kilometers (1.8 miles). The photo shows numerous angular blocks ranging in size from a few centimeters to several meters. The surface between the blocks is composed of fine-grained material. Accumulation of some fine-grained material behind blocks indicates wind deposition of dust and sand downwind of obstacles. The large block on the horizon is about 4 meters (13 feet) wide. Distance across the horizon is about 34 meters (110 feet).<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00385" onclick="window.open(this.href); return false;" title="Voir l'image PIA00385: High Resolution Image From Viking Lander 1 sur le site de la NASA">Voir l'image PIA00385: High Resolution Image From Viking Lander 1 sur le site de la NASA.</a></div>
PIA00385: High Resolution Image From Viking Lander 1
<h1>PIA00386: Example of Weathering And Sun Angle</h1><div class="PIA00386" lang="en" style="width:662px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">The letter 'B' or perhaps the figure '8' appears to have been etched into the Mars rock at the left edge of this picture taken yesterday by the Viking 1 Lander. It is believed to be an illusion caused by weathering processes and the angle of the sun as it illuminated the scene for the spacecraft camera. The object at lower left is the housing containing the surface sampler scoop.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00386" onclick="window.open(this.href); return false;" title="Voir l'image PIA00386: Example of Weathering And Sun Angle sur le site de la NASA">Voir l'image PIA00386: Example of Weathering And Sun Angle sur le site de la NASA.</a></div>
PIA00386: Example of Weathering And Sun Angle
<h1>PIA00387: Northeast View from Viking Landing Site</h1><div class="PIA00387" lang="en" style="width:490px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">This Mars view looks northeast from Viking 1 and completes the 360 panorama of the landing site begun earlier with the spacecraft's other camera. A layer of haze can be seen in the Martian sky. Large dark boulders dominate the scene. The largest boulder (center) is about 3 meters (10 feet) wide and one meter (3 feet) high. Rocks in the foreground are lighter and appear mottled. The rocks may have been derived from lava flows or stream deposits which are visible on orbiter images. These deposits may have been redistributed by impact craters. The fine material visible between the rocks has dune morphology and appears to have been deposited by wind.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00387" onclick="window.open(this.href); return false;" title="Voir l'image PIA00387: Northeast View from Viking Landing Site sur le site de la NASA">Voir l'image PIA00387: Northeast View from Viking Landing Site sur le site de la NASA.</a></div>
PIA00387: Northeast View from Viking Landing Site
<h1>PIA00388: The United States Flag Stands On The Surface Of Mars</h1><div class="PIA00388" lang="en" style="width:508px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">The flag of the United States stands on the surface of Mars. It is mounted on the housing of Viking 1's nuclear power system. Also seen are the U.S. Bicentennial symbol and a student designed Viking emblem. The bright flat surface near the center is the seismometer container. This picture was taken on July 23 at about 2:30 p.m. Mars time. The view is west of the spacecraft and includes a series of low hills. The blocky hill in the center appears to be part of a crater rim. The dark, rocky stripes may be material ejected from the crater. The light areas are dune-like and may be accumulations of windblown sand or dust.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00388" onclick="window.open(this.href); return false;" title="Voir l'image PIA00388: The United States Flag Stands On The Surface Of Mars sur le site de la NASA">Voir l'image PIA00388: The United States Flag Stands On The Surface Of Mars sur le site de la NASA.</a></div>
PIA00388: The United States Flag Stands On The Surface Of Mars
<h1>PIA00391: Sand Dunes And Large Rocks Revealed By Camera 1</h1><div class="PIA00391" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">Sand dunes and large rocks are revealed in this panorama picture of Mars, the first photograph taken by Viking l's Camera 1 on July 23. The horizon is approximately 3 kilometers (2 miles) away. The left and right thirds of this picture are the same areas that were photographed on July 20 (Sol O) by Camera 2 and provide stereo coverage. The middle third reveals a part of the Martian surface not seen on the July 20 panorama. The late afternoon sun is high in the sky over the left side of the picture. The support struts of the S-band high-gain antenna extend to the top of the picture. The American flags are located on the two RTG (Radioisotope Thermoelectric Generator) wind screens. In the middle third of the picture, the rocky surface is covered by thick deposits of wind-blown material, forming numerous dunes. At the center of the picture on the horizon are two low hills which may be part of the rim of a distant crater. Two very large rocks are visible in the middleground; the nearer one is 3 meters (10 feet) in diameter and is 8 meters (25 feet) from the spacecraft. A cloud layer is visible halfway between the horizon and the top of the picture. The meteorology boom is located right of center. Behind it, the 'White Mesa' is visible, which could be seen on the far left side of the Sol O Camera 2 panorama. In the near ground are numerous rocks about 10 cm (4 inches) across, with horseshoe-shaped scour marks on their upwind side and wind tails in their lee. The fine-grained material in front of them contains small pits formed by impact of material kicked out by the Lander spacecraft's rocket engines.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00391" onclick="window.open(this.href); return false;" title="Voir l'image PIA00391: Sand Dunes And Large Rocks Revealed By Camera 1 sur le site de la NASA">Voir l'image PIA00391: Sand Dunes And Large Rocks Revealed By Camera 1 sur le site de la NASA.</a></div>
PIA00391: Sand Dunes And Large Rocks Revealed By Camera 1
<h1>PIA00392: The Meteorology Instrument on Viking Lander 1</h1><div class="PIA00392" lang="en" style="width:355px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">Those Martian weather reports, received here daily from more than 200 million miles away, start right here at Viking l's meteorology instrument. Mounted atop the extended boom, the meteorology sensors face away from the spacecraft. They stand about four feet above the surface and measure atmospheric pressure, temperature, wind velocity and wind direction. The cable parallel to the boom is connected inside the spacecraft body with the electronics for operating the sensors, reading the data and preparing it for transmission to Earth. A second Mars weather station will begin operation next month when Viking 2 lands somewhere in the planet's northern latitude Viking 2 arrives at Mars and goes into orbit tomorrow (August 7).<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00392" onclick="window.open(this.href); return false;" title="Voir l'image PIA00392: The Meteorology Instrument on Viking Lander 1 sur le site de la NASA">Voir l'image PIA00392: The Meteorology Instrument on Viking Lander 1 sur le site de la NASA.</a></div>
PIA00392: The Meteorology Instrument on Viking Lander 1
<h1>PIA00393: Martian Dune Field</h1><div class="PIA00393" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">This spectacular picture of the Martian landscape by the Viking 1 Lander shows a dune field with features remarkably similar to many seen in the deserts of Earth. The dramatic early morning lighting - 7:30 a.m. local Mars time--reveals subtle details and shading. Taken yesterday (August 3) by the Lander s camera #1, the picture covers 100 , looking northeast at left and southeast at right. Viking scientists have studied areas very much like the one in this view in Mexico and in California (Kelso, Death Valley, Yuma). The sharp dune crests indicate the most recent wind storms capable of moving sand over the dunes in the general direction from upper left to lower right. Small deposits downwind of rocks also indicate this wind direction. Large boulder at left is about eight meters (25 feet) from the spacecraft and measures about one by three meters (3 by 10 feet). The meteorology boom, which supports Viking s miniature weather station, cuts through the picture s center. The sun rose two hours earlier and is about 30 above the horizon near the center of the picture.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00393" onclick="window.open(this.href); return false;" title="Voir l'image PIA00393: Martian Dune Field sur le site de la NASA">Voir l'image PIA00393: Martian Dune Field sur le site de la NASA.</a></div>
PIA00393: Martian Dune Field
<h1>PIA00395: The Collector Head Of Viking Lander 1's Surface Sampler</h1><div class="PIA00395" lang="en" style="width:259px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">The collector head of Viking l's surface sampler is full of Martian soil destined for the gas chromatograph mass spectrometer, the instrument which analyzes the surface material for the presence of organic molecules. The material was scooped out of the surface on August 3, but the sampler arm stopped operating while transporting it to the instrument. The Martian soil will be deposited into the instrument's processor today. The surface sampler is operating properly, but the cause of last week's problem is not yet known. This picture, taken Monday (August 9), was made for operational purposes, focusing on the collector head. Hence, the out-of-focus view of the Martian surface.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00395" onclick="window.open(this.href); return false;" title="Voir l'image PIA00395: The Collector Head Of Viking Lander 1's Surface Sampler sur le site de la NASA">Voir l'image PIA00395: The Collector Head Of Viking Lander 1's Surface Sampler sur le site de la NASA.</a></div>
PIA00395: The Collector Head Of Viking Lander 1's Surface Sampler
<h1>PIA00396: Viking Lander 2's First Picture On The Surface Of Mars</h1><div class="PIA00396" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">Viking 2 s first picture on the surface of Mars was taken within minutes after the spacecraft touched down on September 3. The scene reveals a wide variety of rocks littering a surface of fine-grained deposit. Boulders in the 10 to 20-centimeter (4 to 8-inch) size range-- some vesicular (holes) and some apparently fluted by wind--are common. Many of the pebbles have tabular or platy shapes, suggesting that they may be derived from layered strata. The fluted boulder just above the Lander s footpad displays a dust-covered or scraped surface, suggesting it was overturned or altered by the foot at touchdown. Just as occurred with Viking l s first picture on July 20, brightness variations at the beginning of the picture scan (left edge) probably are due to dust settling after landing. A substantial amount of fine-grained material kicked up by the descent engines has accumulated in the concave interior of the footpad. Center of the image is about 1.4 meters (5 feet) from the camera. Field of view extends 70 from left to right and 20 from top to bottom. Viking 2 landed at a region called Utopia in the northern latitudes about 7500 kilometers (4600 miles) northeast of Viking l s landing on the Chryse plain 45 days earlier.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00396" onclick="window.open(this.href); return false;" title="Voir l'image PIA00396: Viking Lander 2's First Picture On The Surface Of Mars sur le site de la NASA">Voir l'image PIA00396: Viking Lander 2's First Picture On The Surface Of Mars sur le site de la NASA.</a></div>
PIA00396: Viking Lander 2's First Picture On The Surface Of Mars
<h1>PIA00397: Boulder 'Big Joe' And Surface Changes On Mars</h1><div class="PIA00397" lang="en" style="width:728px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">This pair of pictures from Viking Lander 1 at Mars' Chryse Planitia shows the only unequivocal change in the Martian surface seen by either lander. Both images show the one-meter (3-foot) high boulder nicknamed 'Big Joe.' Just to the lower right of the rock (right photo) is a small-scale slump feature. The picture at left shows a smooth, dust-covered slope; in the picture at right the top surface layer can be seen to have slipped downslope. The event occurred sometime between Oct. 4, 1976, and Jan 24, 1977. (Pictures taken before Oct. 4 do not show the slump; the first picture in which it appears was taken Jan. 24.) The surface layer, between one-half and one centimeter (one-fifth to one-third inch) thick, is apparently less cohesive than the underlying material. The layer that slipped formed a 30-centimeter-long (11.8-inch) 'tongue' of soil and a patch of exposed underlying material. The triggering mechanism for the event is unknown, but could have been temperature variations, wind gusts, a seismic event, or perhaps the lander's touchdown on July 20, 1976.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00397" onclick="window.open(this.href); return false;" title="Voir l'image PIA00397: Boulder 'Big Joe' And Surface Changes On Mars sur le site de la NASA">Voir l'image PIA00397: Boulder 'Big Joe' And Surface Changes On Mars sur le site de la NASA.</a></div>
PIA00397: Boulder 'Big Joe' And Surface Changes On Mars
<h1>PIA00398: Surface Sampler Arm</h1><div class="PIA00398" lang="en" style="width:439px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">Photographic evidence of the successful series of commands to the Viking 1 lander on Mars that unlocked the surface sampler arm is seen in this picture. At lower left, to the right of a whitish area is a small oblong object -- the boom latch pin that had failed to drop out of the scoop assembly causing the mechanism to lock. With the pin free, the boom and scoop can now be used for the soil sampler experiments beginning in two days, including a search for microscopic life in the Martian soil. The boom latch pin is 0.2 inches in diameter and 3.2 inches long. The pin weights 0.44 ounces, fell from about three feet and impacted the surface at eight to nine feet per second producing a mini-crater with a dark ejecta blanket. These data will be studies to determine soil properties.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00398" onclick="window.open(this.href); return false;" title="Voir l'image PIA00398: Surface Sampler Arm sur le site de la NASA">Voir l'image PIA00398: Surface Sampler Arm sur le site de la NASA.</a></div>
PIA00398: Surface Sampler Arm
<h1>PIA00399: Northern Plains Of Mars</h1><div class="PIA00399" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">This rocky panoramic scene is the second picture of the Martian surface that was taken by Viking Lander 2 shortly after touchdown on September 3 at 3:58 PM PDT (Earth received time). The site is on a northern plain of Mars, at about 48 N. Lat., 226 W. Long., known as Utopia Planitia. The picture sweeps around 330 degrees in azimuth, starting from northwest at the left through north (above the sampler arm housing) past east, where the sky is bright at the center, and southeast toward the right above the radioisotope thermoelectric generator cover. The surface is strewn with rocks out to the horizon, ranging in size up to several meters across. Some pitted rocks resemble fragments of porous volcanic lava. Other rocks have grooves that may have been eroded by windblown sand and dust. Although fine-grained material is seen between the boulders, no sand dunes are evident. The dip in the eastern horizon at the center is an illusion caused by an 8-degree tilt of the Lander toward the west. Actually, the terrain is more level than that at the Viking 1 site. The horizon toward the left of the panorama (northwest) appears featureless, indicating that it may be several kilometers distant. The sky at the center (east) is bright because the sun was above but out of the picture at 10 AM Mars time. Toward the right (southeast), the rocks that are silhouetted against the skyline indicate that the horizon is much nearer, probably because of a slight rise in that area of the terrain. The circular high-gain antenna at the right has clots of fine-grained material adhering to the lower half, some of which appeared to have been sliding downward while the camera was scanning the area. At the extreme right, the banded appearance resulted because the camera continued to scan while it was no longer moving in azimuth. Any motion or other variation in the scene would show up as a change in successive lines.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00399" onclick="window.open(this.href); return false;" title="Voir l'image PIA00399: Northern Plains Of Mars sur le site de la NASA">Voir l'image PIA00399: Northern Plains Of Mars sur le site de la NASA.</a></div>
PIA00399: Northern Plains Of Mars
<h1>PIA00403: West Candor Chasma</h1><div class="PIA00403" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">During its examination of Mars, the Viking 1 spacecraft returned images of Valles Marineris, a huge canyon system 5,000 km long, up to 240 km wide, and 6.5 km deep, whose connected chasma or valleys may have formed from a combination of erosional collapse and structural activity. The view shows west Candor Chasma, one of the connected valleys of Valles Marineris; north toward top of frame. The image is a composite of Viking high-resolution (about 80 m/pixel or picture element) images in black and white and low resolution (about 250 m/pixel) images in color. The Viking 1 craft landed on Mars in July of 1976. West Candor Chasma occupies the westernmost part of the large west-northwest-trending trough of Candor Chasma. This section is about 150 km wide. West Candor Chasma is bordered on the north and south by straight-walled cliffs, most likely faults, and on its west by two segments of north-northeast-trending cliffs. The north wall is dissected by landslide scars forming reentrants filled with landslide debris. The south wall shows spur-and-gully morphology and smooth sections. The high-standing central mesa, informally dubbed Red Mesa has several curvilinear reentrants carved into the caprock, whose anomalously colored layers were interpreted to be caused by young hydrothermal alteration products (Geissler et al., 1993, Icarus, v. 106, p. 380-391). Light-colored lobes flow away from the top of the interior stack and then flow around and embay the same layered stack from which they originated. One of these apparent flow features is composed of at least two or perhaps even three huge, superposed, vaguely layered, very rugged, light-colored lobes as much as 100 km long, 20 km wide, and over 2 km thick. The layered deposits below the caprock also merge with a chaotic material that has local lobate fronts and overlaps landslide deposits. Hummocky material, similar in hue to wall rock, fills the southwestern-most region of west Candor Chasma and is perhaps as much as 3 km thick (Lucchitta, 1990, Icarus, v. 86, p. 476- 509). The light-colored lobes, chaotic material, and hummocky fill may be mass wasting deposits due to wholesale collapse of older interior deposits (Lucchitta, 1996, LPSC XXVII abs., p. 779- 780); this controversial idea requires that the older layered deposits were saturated with ice, perhaps from former lakes and that young volcanism and/or tectonism melted the ice and made the material flow.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00403" onclick="window.open(this.href); return false;" title="Voir l'image PIA00403: West Candor Chasma sur le site de la NASA">Voir l'image PIA00403: West Candor Chasma sur le site de la NASA.</a></div>
PIA00403: West Candor Chasma
<h1>PIA00407: Global Color Views of Mars</h1><div class="PIA00407" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">About 1000 Viking Orbiter red- and violet-filter images have been processed to provide global color coverage of Mars at a scale of 1 km/pixel. Individual image frames acquired during a single spacecraft revolution were first processed through radiometric calibration, cosmetic cleanup, geometric control, reprojection, and mosaicing. We have produced a total of 57 "single-rev" mosaics. All of the mosaics are geometrically tied to the Mars Digital Image Mosaic, a black-and-white base map with a scale of 231 m/pixel. We selected a subset of single-rev mosaics that provide the best global coverage (least atmospheric obscuration and seasonal frost); photometric normalization was applied to remove atmospheric effects and normalize the variations in illumination and viewing angles. Finally, these normalized mosaics were combined into global mosaics. Global coverage is about 98% complete in the red-filter mosaic and 95% complete in the violet-filter mosaic. Gaps were filled by interpolation. A green-filter image was synthesized from an average of the red and violet filter data to complete a 3-color set. The Viking Orbiters acquired actual green-filter images for only about half of the Martian surface. The final mosaic has been reprojected into several map projections. The orthographic view shown here is centered at 20 degrees latitude and 60 degrees longitude. The orthographic view is most like the view seen by a distant observer looking through a telescope. The color balance selected for these images was designed to be close to natural color for the bright reddish regions such as Tharsis and Arabia, but the data have been "stretched" such that the relatively dark regions appear darker and less reddish that their natural appearance. This stretching allows us to better see the color and brightness variations on Mars, which are related to the composition or physical structure of the surface materials, which include volcanic lava flows, wind- and water-deposited sedimentary rocks, and (at the poles) ice caps. The north polar cap is visible in this projection at the top of the image, the great equatorial canyon system (Valles Marineris) below center, and four huge Tharsis volcanoes (and several smaller ones) at left. Also note heavy impact cratering of the highlands (bottom and right portions of this mosaic) and the younger, less heavily cratered terrains elsewhere.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00407" onclick="window.open(this.href); return false;" title="Voir l'image PIA00407: Global Color Views of Mars sur le site de la NASA">Voir l'image PIA00407: Global Color Views of Mars sur le site de la NASA.</a></div>
PIA00407: Global Color Views of Mars
<h1>PIA00408: Tharsis</h1><div class="PIA00408" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>A color image of the Tharsis region of Mars; north toward top. The scene shows the Tharsis bulge, a huge ridge covered by the 3 large aligned Tharsis Montes shield volcanoes (from lower left to right): Arsia, Pavonis, and Ascraeus Mons. To the left of the Tharsis Montes lies the huge Olympus Mons shield volcano, followed clockwise by Alba Patera (north center), several smaller volcanoes, and the linear depressions of Mareotis and Tempe Fossae (upper right).</p><p>This image is a composite of Viking medium-resolution images in black and white and low-resolution images in color. The image extends from latitude 50 degrees N. to 20 degrees S. and from longitude 85 degrees to 150 degrees. Mercator projection is used between latitudes 20 degrees S. and 30 degrees N.; Lambert projection is used above latitude 30 degrees N.</p><p>The Tharsis bulge encompasses the most intensely and most recently active volcanic region of the planet. Each Tharsis Montes volcano is 350-400 km in diameter and about 17 km above the surrounding plain. The volcanoes are about 700 km apart and appear to be above a major northeast-trending fracture zone along the bulge, now buried by volcanic deposits. Olympus Mons (left center) is the largest known volcano in the Solar System. It is 27 km high, over 600 km at the base, and is surrounded by a well-defined scarp that is up to 6 km high. The summit calderas (central depressions) of all four volcanoes probably formed from recurrent collapse following drainage of magma resulting from flank eruptions. 1,600-km-diameter Alba Patera (north center) far exceeds any other known volcano in areal extent; it covers eight times the area of Olympus Mons but reaches only about 6 km in height. Fossae (linear depressions) of the Tharsis area are fault-bound graben formed by upwarping of the Tharsis bulge.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00408" onclick="window.open(this.href); return false;" title="Voir l'image PIA00408: Tharsis sur le site de la NASA">Voir l'image PIA00408: Tharsis sur le site de la NASA.</a></div>
PIA00408: Tharsis
<h1>PIA00409: Alba Patera</h1><div class="PIA00409" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>A color image of the Alba Patera region of Mars; north toward top. The scene shows a central circular depression surrounded by splays of fractures, named Alba Fossae (west of Alba Patera) and Tantalus Fossae (east of Alba Patera). A patera (Latin for shallow dish or saucer) is a volcano of broad areal extent with little vertical relief; a fossa is a linear depression.</p><p>This image is a composite of Viking medium-resolution images in black and white and low-resolution images in color. The image extends from latitude 30 degrees N. to 50 degrees N. and from longitude 95 degrees to 125 degrees; Lambert projection.</p><p>Alba Patera has a 100-km-diameter caldera at its center surrounded by a fracture ring. In total, the approximately 1,200- km-diameter Alba Patera far exceeds any other known volcano in areal extent; it covers eight times the area of Olympus Mons (the highest volcano in the Solar System) but reaches only about 6 km in height. The patera lies directly north of the Tharsis bulge, which encompasses the most intensely and most recently active volcanic region of the planet. The fossae of the Alba area are fault-bound graben that can be traced south through the Tharsis bulge and therefore likely formed by upwarping of the Tharsis bulge as well as the coeval upwelling of Alba Pateria magma.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00409" onclick="window.open(this.href); return false;" title="Voir l'image PIA00409: Alba Patera sur le site de la NASA">Voir l'image PIA00409: Alba Patera sur le site de la NASA.</a></div>
PIA00409: Alba Patera
<h1>PIA00410: Amphitrites Patera</h1><div class="PIA00410" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>A color image of the Amphitrites Patera region of Mars; north toward top. The scene shows several indistinct ring structures and radial ridges of an old volcano named Amphitrites Patera. A patera (Latin for shallow dish or saucer) is a volcano of broad areal extent with little vertical relief.</p><p>This image is a composite of Viking medium-resolution images in black and white and low-resolution images in color. The image extends from latitude 55 degrees S. to 62 degrees S. and from longitude 292 degrees to 311 degrees; Lambert projection.</p><p>Amphitrites Patera is a 138-km-diameter feature on the south rim of Hellas impact basin and is one of many indistinct ring structures in the area. The location of the paterae in this area of Hellas indicates that their source magma may have been influenced by the transition fractures of the basin. The radial ridges of Amphitrites extend for about 400 km north into the Hellas basin.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00410" onclick="window.open(this.href); return false;" title="Voir l'image PIA00410: Amphitrites Patera sur le site de la NASA">Voir l'image PIA00410: Amphitrites Patera sur le site de la NASA.</a></div>
PIA00410: Amphitrites Patera
<h1>PIA00411: Apollinaris Patera</h1><div class="PIA00411" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>A color image of the Apollinaris Patera Region of Mars; north toward top. The scene shows the 80-km-wide central caldera of Apollinaris, a plume of young flows extending south down the flank of the volcano, a cliff and chaotic terrain west of the volcano, and the surrounding younger deposits of the Medusae Fossae Formation (north and east). A patera (Latin for shallow dish or saucer) is a volcano of broad areal extent with little vertical relief.</p>This image is a composite of Viking medium-resolution images in black and white and low-resolution images in color. The image extends from latitude 12 degrees S. to 6 degrees S. and from longitude 182 degrees to 189 degrees; Mercator projection.</p>Apollinaris Patera is an isolated volcano (about 400 km across) lying on the Martian highlands just north of Gusev impact crater and the termination of Ma'adim Vallis. After the main edifice was built, eruption continued on the volcano's southern flank to form a broad ridge overlapping the original shield. Breakdown of ice-rich materials formed chaos on its western edge. Finally the friable materials (possible ash?) of the Medusae Fossae Fm were deposited.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00411" onclick="window.open(this.href); return false;" title="Voir l'image PIA00411: Apollinaris Patera sur le site de la NASA">Voir l'image PIA00411: Apollinaris Patera sur le site de la NASA.</a></div>
PIA00411: Apollinaris Patera
<h1>PIA00412: Elysium</h1><div class="PIA00412" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>A color image of the Elysium Region of Mars; north toward top. The scene shows the Elysium Mons volcano (center), Hecates Tholus (to the north), Albor Tholus (to the south), and the depressions of Elysium Fossae. Mons is a Latin term for mountain; the term tholus designates a small mountain or dome.</p>This image is a composite of Viking medium-resolution images in black and white and low-resolution images in color. The image extends from latitude 16 degrees N. to 35 degrees N. and from longitude 206 degrees to 220 degrees; Mercator projection.</p>The Elysium region contain the second largest volcanic complex on Mars, surpassed in size by only the Tharsis complex. Elysium Mons, whose summit elevation is 16,000 m above the Martian datum, is at the crest of a regional topographic rise that emerges steeply and abruptly from the surrounding plains. The relief of Hecates is about 6,000 m and the relief of Albor is only about 4,000 m, because Hecates is on the edge of the rise whereas Albor is on it. After degradation of ancient cratered terrain within the northern lowlands, volcanic rocks erupted from Elysium Mons, Hecates Tholus, and Albor Tholus in Elysium Planitia. Elysium Fossae are volcano/tectonic troughs that parallel graben in the area. Some troughs are connected with channels to the east indicating an interaction between volcanic and hydrothermal systems.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00412" onclick="window.open(this.href); return false;" title="Voir l'image PIA00412: Elysium sur le site de la NASA">Voir l'image PIA00412: Elysium sur le site de la NASA.</a></div>
PIA00412: Elysium
<h1>PIA00413: Fine Channel Networks</h1><div class="PIA00413" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>A color image of fine channel networks on Mars; north toward top. The scene shows heavily cratered highlands dissected by dendritic open channel networks that dissect steep slopes of impact crater walls.</p>This image is a composite of Viking high-resolution images in black and white and low-resolution images in color. The image extends from latitude 9 degrees S. to 5 degrees S. and from longitude 312 degrees to 320 degrees; Mercator projection.</p>The dendritic pattern of the fine channels and their location on steep slopes leads to the interpretation that these are runoff channels. The restriction of these types of channels to ancient highland rocks suggests that these channels are old and date from a time on Mars when conditions existed for precipitation to actively erode rocks. After the channels reach a low plain, they appear to end. Termination may have resulted from burial by younger deposits or perhaps the flows percolated into the surface materials and continued underground.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00413" onclick="window.open(this.href); return false;" title="Voir l'image PIA00413: Fine Channel Networks sur le site de la NASA">Voir l'image PIA00413: Fine Channel Networks sur le site de la NASA.</a></div>
PIA00413: Fine Channel Networks
<h1>PIA00414: Ma'adim Vallis</h1><div class="PIA00414" lang="en" style="width:563px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;">Color image of Ma'adim Vallis region of Mars; north toward top. Image shows the 600-km-long channel that drained into impact crater Gusev. Crater Gusev is about 160 km in diameter. This image is a composite of Viking medium-resolution images in black and white and low-resolution images in color. The image extends from latitude 13 degrees S. to 29 degrees S. and from longitude 180 degrees to 188 degrees; Mercator projection. Ma'adim Vallis is cut into the degraded highlands of Mars and has morphologic characteristics of terrestrial river beds, including the well-developed dentritic tributaries that constitute an integrated river system. However, the junction angles between tributaries commonly show a wide variation, which gives the channel system a more random directional pattern than typical terrestrial drainage networks. Topographic contours suggest a large drainage basin once existed for this channel. Gradients for the channel are high, about 0.007, over the central 300 km of its length; this is about two times that of the upper 450 km of the Colorado River. In places, some tributaries are discontinuous, perhaps indicating burial by more recent material. After the channel breaches Gusev it appears to end within the crater. Termination may have resulted from burial by younger deposits or perhaps the flow percolated into the surface materials and continued underground.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00414" onclick="window.open(this.href); return false;" title="Voir l'image PIA00414: Ma'adim Vallis sur le site de la NASA">Voir l'image PIA00414: Ma'adim Vallis sur le site de la NASA.</a></div>
PIA00414: Ma'adim Vallis
<h1>PIA00415: Hadriaca Patera</h1><div class="PIA00415" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>A color image of Hadriaca Patera on the northeast rim of Hellas basin of Mars; north toward top. The scene shows a central circular depression surrounded by low radial ridges and, at the bottom of the image, the channel of Dao Vallis. A patera (Latin for shallow dish or saucer) is a volcano of broad areal extent with little vertical relief.</p><p>This image is a composite of Viking medium-resolution images in black and white and low-resolution images in color. The image extends from latitude 27 degrees S. to 37 degrees S. and from longitude 263 degrees to 273 degrees; Mercator projection.</p><p>Hadriaca Patera is less than 2 km high, has a 60-km-diameter caldera at its center, and is surrounded by a 300-km-wide ring of low ridges. The radial ridges may be lava flows with lava channels at their crests. South of Hadriaca, Dao Vallis begins at a steep-walled depression 40 km across but forms a much shallower channel that extends 800 km southwest into the floor of the Hellas basin. The channel is very likely fluvial in origin, with the release of water being triggered by volcanic activity.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00415" onclick="window.open(this.href); return false;" title="Voir l'image PIA00415: Hadriaca Patera sur le site de la NASA">Voir l'image PIA00415: Hadriaca Patera sur le site de la NASA.</a></div>
PIA00415: Hadriaca Patera
<h1>PIA00416: Hellas Planitia</h1><div class="PIA00416" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>A color image of the Hellas Planitia region of Mars; north toward top. The scene shows the Hellas plain within the 1,800- km-diameter Hellas basin, an ancient impact basin (and the largest basin on Mars) formed when a large projectile (asteroid, comet, meteor) hit the surface.</p><p>This image is a composite of Viking medium-resolution images in black and white and low-resolution images in color. The image extends from latitude 60 degrees S. to 20 degrees S. and from longitude 250 degrees to 320 degrees. Mercator projection is used between latitudes 20 degrees S. and 30 degrees S.; Lambert projection is used below latitude 30 degrees S.</p><p>The exact diameter of the ancient Hellas basin is difficult to determine because large portions of the rim are missing to the northeast and southwest. In addition several large patera or low volcanoes (Tyrrhena, Hadriaca, Amphitrites) occur along or near the rim and their flows have partially buried the older impact deposits. Outside the rim are several large, arcuate, inward-facing escarpments which could be remnants of multiple rings. The plains of Hellas are very complex; fluvial channels drain into the basin and the plains have been described as being a mixture of fluvial, lacustrine, glacial, eolian, and volcanic deposits. Frequent dust storms occur within the basin.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00416" onclick="window.open(this.href); return false;" title="Voir l'image PIA00416: Hellas Planitia sur le site de la NASA">Voir l'image PIA00416: Hellas Planitia sur le site de la NASA.</a></div>
PIA00416: Hellas Planitia
<h1>PIA00417: Nilosyrtis Mensae</h1><div class="PIA00417" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>A color image of part of the Nilosyrtis Mensae region of Mars containing the impact craters Antoniadi and Baldet (south to north) in the lower left corner; north toward top. The scene shows heavily cratered highlands on the south separated from the relatively smooth lowland plains on the northeast corner by a belt of dissected terrain, containing flat-floored valleys, mesas, buttes, and channels. The channels are (left to right) Auqakuh and Huo Hsing Valles; Nili Fossae lie in lower right corner of image.</p><p>This image is a composite of Viking medium-resolution images in black and white and low-resolution images in color. The image extends from latitude 20 degrees N. to 40 degrees N. and from longitude 280 degrees to 305 degrees. Mercator projection is used below 30 degrees N.; Lambert projection is used above 30 degrees N.</p><p>The dissected terrain along the highlands/lowlands boundary consist of the flat-floored valleys (mensae) and farther north the small, rounded hills of knobby terrain. Flows on the mensa floors contain striae that run parallel to valley walls; where valleys meet, the striae merge, similar to medial moraines on glaciers. Terraces within the valley hills have been interpreted as either layer rocks or wave terraces. The knobby terrain has been interpreted as remnants of the old, densely cratered highland terrain perhaps eroded by mass wasting. Auqakuh and Huo Hsing Valles and Nili Fossae are fretted channels and linear depressions that likely formed by sapping and mass wasting along lines of structural weakness.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA00417" onclick="window.open(this.href); return false;" title="Voir l'image PIA00417: Nilosyrtis Mensae sur le site de la NASA">Voir l'image PIA00417: Nilosyrtis Mensae sur le site de la NASA.</a></div>
PIA00417: Nilosyrtis Mensae

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