Last chance to join our Costa Rica Star Party! Learn about the Moon in a great new book New book chronicles the space program. Dave's Universe Year of Pluto. Groups Why Join? Astronomy Day. The Complete Star Atlas. Valles Marineris, the great canyon of Mars that stretches for more than 2, miles 4, kilometers and is up to 4.
The lithosphere is the solid, uppermost portion of the planet that sits above the partly molten mantle. This cold lithosphere has a great deal of strength and can hold up the large martian volcanoes such as Olympus Mons.
As on Earth, the mantle of the Red Planet is slowly moving, or convecting, which produces stretching and pulling forces at the bottom of the lithosphere. On our planet, these forces are strong enough to break the lithosphere into plates that can move apart, creating continental drift and plate tectonics. Colonizing Mars could speed up human evolution. Snapshot : Martian string of craters. How would humans decompose on Mars?
The Hesperian's timespan is known only roughly, but is thought to extend from about 3. During this time, besides the massive flooding and the growth of Tharsis, Mars experienced a slowing rate of impacts making craters and basins, and the climate shifted to colder and drier conditions.
Weakening Resistance. Not all the erosion within the valley produced catastrophic floods. In places such as Louros Valles, where numerous tributary canyons cut into the valley's southern rim, canyon widening and erosion occurred on smaller scales. These canyons likely formed by the same method as the main valley segments - release of groundwater - but the quantity of water was less, the scale was smaller, and the results more localized. As geologists reconstruct it, water emerged from the canyon walls as springs and seeps and carried away sediment.
In its wake, this sapping process left round-headed valleys that slowly retreated from the rim of the canyon. As faults and cracks in the rock guided the sapping, the growing valleys developed a characteristic tree-branch shape. It's worth comparing the tributary canyon seen here to the Grand Canyon in northern Arizona. The Grand Canyon is about kilometers miles long, while this tributary is only kilometers 72 miles long. But where this valley empties into Valles Marineris, it is more than 3, meters 12, feet deep - over twice the depth of Earth's Grand Canyon.
Groundwater's effects can be seen also with the crater at bottom center. About 7 km 4. Scientists call this a rampart crater, and they believe the skirt shows the ground held a lot of water or ice at the time of impact.
The heat of the blast released the water and lubricated the flying debris, producing a semi-solid splash pattern edged by the rampart, which is about 70 meters feet high. Making Landfall. Undermined cliffs and valley walls are usually unstable, and Valles Marineris has grown wider in many places through landslides. This particular slide dropped thousands of feet and has a maximum length of about kilometers 60 miles.
A closer look at it shows that several landslides have occurred here, with each now slide lying on top of the previous ones. As examples on Earth show, landslides can travel great distances, especially when the debris contains trapped water or air to lower friction. Scientists think it likely that even the thin air of Mars would have contributed to this slide's remarkable run.
Similar, if shorter, landslides lie throughout most of Valles Marineris, and helped to widen the canyon as it developed. The Story Plateaus and spurs might make you think of cowboys on the open plain. Gullies stretch down this slope as well. Both of these features are caused by erosion, which is a mild force of change compared to whatever tension cracked the crust and ripped apart the land.
The wall rock displayed in the upper part of the cliffs appears to be layered, suggesting that different kinds of rocks and minerals can be found in each banded zone. The Ophir Planum plateau separates two separate canyon systems in the Valles Marineris complex, the largest canyon in the solar system.
That will give you some idea of the geological forces that have acted upon the planet over time. Coprates Chasma. This image from NASA Mars Odyssey spacecraft, which displays clearly the contrast between bedrock, sand, and dust surfaces, covers a portion of Coprates Chasma, part of the Valles Marineris system of canyons that stretch for thousands of kilometers. Ophir Planum. The Valles Marineris system of canyons that stretch for thousands of kilometers across Mars are located just south of the area covered in the image.
Melas Chasma Deposits. Erosion of the interior layered deposits of Melas Chasma, part of the huge Valles Marineris canyon system, has produced cliffs with examples of spur and gulley morphology and exposures of finely layered sediments, as seen in this NASA Mars Odyssey image.
Tithonium Chasma has numerous large landslide deposits. The resistant material of the plateau surface forms the linear ridges of the canyon wall. Large landslides have changed the walls and floor of the canyon. A landslide is a failure of slope due to gravity. They initiate due to several reasons. As millions of tons of material fall and slide down slope a scalloped cavity forms at the upper part where the slope failure occurred.
At the material speeds downhill it will pick up more of the underlying slope, increasing the volume of material entrained into the landslide.
Whereas some landslides spread across the canyon floor forming lobate deposits, very large volume slope failures will completely fill the canyon floor in a large complex region of chaotic blocks. This VIS image shows the result of this type of landslide.
Both the north and south canyon walls are visible in this image. At the top of the frame paired faults have created a graben. On the southern face of the canyon , several linear faults parallel the graben. These faults are part of the tectonic formation of Valles Marineris.
Landslides on both walls created deposits on the crater floor. The easiest to identify is the lobate margin at the right side of the images. Lobate margins and radial surface grooves are common features in low volume landslides. Weathering of the. Investigating Mars: Melas Chasma. Melas Chasma is part of the largest canyon system on Mars, Valles Marineris. At only km long miles it is not the longest canyon , but it is the widest. Located in the center of Valles Marineris , it has depths up to 9 km below the surrounding plains, and is the location of many large landslide deposits, as will as layered materials and sand dunes.
There is evidence of both water and wind action as modes of formation for many of the interior deposits. This VIS image highlights the extent of layered materials within the canyon. The image is located on the mid elevations on the south side of the canyon. The Odyssey spacecraft has spent over 15 years in orbit around Mars, circling the planet more than times. For the next several months the image of the day will focus on the Tharsis volcanoes, the various chasmata of Valles Marineris , and the major dunes fields.
We hope you enjoy these images! Orbit Number: Latitude: Continuing eastward along Ius Chasma, this section of the canyon floor has been completely filled by blocky deposits from large volume landslides.
Eroded materials cover most of the image. The initial formation of layered floor deposits was possibly created of air fall of dust, sand, and volcanic materials and water lain materials. The bottom part of the image has complex, hummocky material, probably very old landslide deposits. At the top of the image is a large mound of material that has been eroded mainly by wind action.
The overlapping of these surfaces indicates a long history of modication of Tithonium Chasma. For the. This VIS image of Tithonium Chasma shows the canyon wall at the top of the frame, a series of landslide deposits in the middle, and an eroded mound of materials at the bottom. The mound has been eroded, most likely by wind action. The Odyssey. Chryse Outflow Channel.
A color image of the south Chryse basin Valles Marineris outflow channels on Mars; north toward top. The scene shows on the southwest corner the chaotic terrain of the east part of Valles Marineris and two of its related canyons : Eos and Capri Chasmata south to north.
The chaos in the southern part of the image gives rise to several outflow channels, Shalbatana, Simud, Tiu, and Ares Valles left to right , that drained north into the Chryse basin. This image is a composite of NASA's Viking medium-resolution images in black and white and low-resolution images in color. The image extends from latitude 20 degrees S. Continuing eastward along Ius Chasma, this image shows the eastern section of the large landslide deposit seen in yesterday's post.
Today's image of the southern section of the canyon shows a large region of sand dunes. The presence of dunes indicates wind action as the most recent geologic process modifying the canyon. Today's image contains a large region of dunes between the canyon cliff face and the large ridge of material at the mid-elevation of the canyon.
Fine materials have been concentrated into the dunes. In this narrow and deep part of the chasma exist both large, chaotic block landslide deposits with smaller lobate shaped landslide deposits on top. The Odyssey spacecraft has. Erosion of the walls cover the lower slopes. As the landslide material reaches the canyon bottom it spreads out and eventually comes to rest. The edge of the deposit is lobate, and may be affected by running up against pre-existing features on the canyon floor.
Most Martian landslide have radial grooves on the slide surface. Weathering of the surface and influx of dust and sand have modified the canyon floor, both creating and modifying layered. Topography of Valles Marineris : Implications for erosional and structural history. The central troughs north Ophir, north and central Candor, and north Melas Chasmata lie as much as 11 km below the adjacent plateaus.
In Ophir and Candor chasmata, interior layered deposits reach 8 km in elevation. If the deposits are lacustrine and if all troughs were interconnected, lake waters standing 8 km high would have spilled out of Coprates Chasma onto the surrounding plateaus having surface elevations of only km.
On the other hand, the troughs may not have been interconnected at the time of interior-deposit emplacement; they may have formed isolated ancestral basins. The existence of such basins is supported by independent structural and stratigraphic evidence.
The peripheral troughs are only km deep, shallower than the central troughs. Chaotic terrain is seen in the peripheral troughs near a common contour level of about 4 km on the adjacent plateaus, which supports the idea of release of water under artesian pressure from confined aquifers. The layered deposits in the peripheral troughs may have formed in isolated depressions that harbored lakes and predated the formation of the deep outflow channels.
If these layered deposits are of volcanic origin, they may have been emplaced beneath ice in the manner of table mountains. Areal and volumetric computations show that erosion widened the troughs by about one-third and that deposits occupy one-sixth of the interior space.
Even though the volume. This VIS image of Tithonium Chasma shows the canyon wall at the top of the frame and the cliff face of the opposite side of the canyon at the bottom of the image.
Most of the floor has been covered with the deposits of large volume landslides. Near the top-right portion of the canyon wall several smaller lobate landslide deposits are visible. Weathering of the surface and influx of. Located in the center of Valles Marineris , it has depths up to 9 km from the surrounding plains, and is the location of many large landslide deposits, as will as layered materials and sand dunes.
This VIS image shows layered materials and sand dunes. In this VIS image a complex region of multiple overlapping landslide deposits fills most the the frame. The very top layer has the lobate edges and radial surface grooves of a low volume slide. It appears to be the top of a complex layering of materials. It is possible that all the lower layers are landslides as well. Whether the layers formed very close in time of over thousands of years can not be determined in the image. Landslides have enlarged the canyon.
The southern canyon wall is at the bottom of the image, with dark sand and sand dunes. The presence of mobile sand indicates that winds are eroding, depositing and changing the canyon floor. The rest of the image is dominated by large landslide deposits.
At the top of the image are two overlapping deposits from landslides originating on the northern chasma wall. The landslide deposit on the left side of the image originate from the southern chasma wall. Weathering of the surface and influx of dust and sand have modified. This VIS image is located along the northern cliff face of the chasma.
The linear features are large landslide surfaces. A region of sand dunes is located along the change in elevation from the cliff face at the top of the image and the floor of the canyon at the bottom of the image. This VIS image is located right at the edge of the canyon with the surrounding plains - the flat area at the bottom of the image. Some small landslide deposits are visible originating at the cliff side. This VIS image shows part of a large ridge of material near the south central part the canyon.
The roughest looking material is the top of the ridge. Landslides in Valles Marineris , Mars. The morphology of the landslides in the Martian equatorial troughs, the geologic structure of the troughs, the time of emplacement, the similarity to terrestrial landslides, and the origin and mechanism of transport are analyzed.
About 35 large landslides well-resolved on Viking images were examined, and it is found that the major landslides cover 31, sq km of the trough floors, and individual slides range in area from 40 to sq km. The morphologic variations of the landslides can be attributed mainly to their degree of confinement on trough floors.
Many prominent landslides appear to be of similar age and were emplaced after a major faulting that dropped the trough floors.
Most sliding occurred after the created scarps were dissected into spurs, gullies, and tributary canyons. Emplacement of the landslides approximately coincided with a late episode of major eruptive activity of the Tharsis volcanoes, and it is suggested that the slides may have originated as gigantic mudflows with slump blocks at their heads. The large size of many landslides is due to the fault scarps as high as 7 km on which they formed in the absence of vigorous fluvial erosion.
The landslides suggest that Mars is earthlike in some respects, which may be important for further evaluations. Continuing eastward thru central Ius Chasma, this image shows a section of chasma that is not dominated by landslide deposits.
Geryon Montes, in the upper half of the image, has several visible faults, including a pair of faults that divide the uppermost ridge into two sections. Between the montes and the southern wall face is a region of sand and sand dunes.
Weathering of the surface and influx of dust and sand have modified the canyon floor, both creating and modifying. Geryon Montes are located in the bottom half of the image.
The top of the image is dominated by a large landslide deposit. The radial surface grooves are still visible, but the region as a whole as undergone significant erosion. Weathering of the surface and influx of dust and sand have modified the canyon floor, both creating and.
This map product contains a set of three ,scale maps showing the geology and structure of study areas in the western Candor Chasma region of Valles Marineris , Mars. These maps are part of an informal series of large-scale maps and map-based topical studies aimed at refining current understanding of the geologic history of western Candor Chasma. These maps are accompanied by geologic cross sections, colorized elevation maps, and cutouts of HiRISE images showing key superposition relations.
Also included in this product is a Correlation of Map Units that integrates units across all three map areas, as well as an integrated Description of Map Units and an integrated Explanation of Map Symbols.
The ArcGIS projects and databases associated with each map are included online as supplemental data. The lower elevations of Geryon Montes are located at the top of the image. The texture of the canyon floor beneath the dunes and elsewhere in the image is an indication of water, in some form, was part of the process creating the surface.
There is a tongue of material emerging from the canyon wall that has steep sides, this may be a delta formed by material washing down the valley and into a body of standing water, like a lake. It may also just be a landslide deposit that has undergone extensive weathering. The canyons of Valles Marineris were formed by extensive. In the center of the image the top layer has the lobate edges and radial surface grooves of a low volume slide.
It appears to be the top of a complex layering of materials, It is possible that all the lower layers are landslides as well. At the top of the image are a series of smaller lobate shaped landslide deposits Whether the layers formed very close in time of over thousands of years can not be determined in the image.
The canyons of Valles Marineris were formed by extensive fracturing and pulling. Deposition and deformation of stratified rocks in the northern Nia Mensa region of Valles Marineris , Mars. The map area encompasses the contact between massive sedimentary rocks that comprise most of Nia Mensa and the stratified sedimentary and mass-wasting deposits exposed between Nia Mensa and the north wall of eastern Candor Chasma.
The area contains a stratified fan-like deposit on the lower slopes of Nia Mensa. The strata within this deposit dip outward at Investigating Mars: Melas Chasma. Today's image covers part of the floor of the canyon. At the top of the image is one of the many hills found on the floor in this region. The linear grooved surface is part of a landslide deposit. Melas Chasma has many large landslide regions. Landslide deposits often have grooved surfaces with the grooves parallel to the direction of movement as the slide occurred.
The ends of the landslide typically have a lobate edge, and will flow around large preexisting landforms. Investigating Mars: Candor Chasma. Near the bottom of the image is an impact crater. Impact craters are relatively rare within all the canyons of Valles Marineris. The lack of craters may be due to the relative young age of the canyon system - younger surfaces on Mars have fewer craters than older surfaces. Another factor is that the high rate of erosion and deposition within the canyon erodes the ejecta blanket and fills in the crater, effectively removing the crater over time.
Candor Chasma is one of the largest canyons that make up Valles Marineris. It is approximately km long miles and has is divided into two regions - eastern and western Candor. Candor is located south of Ophir Chasma and north of Melas Chasma. The border with Melas Chasma contains many large landslide deposits. The floor of Candor Chasma includes a variety of landforms, including layered deposits, dunes, landslide deposits and steep sided cliffs and mesas.
Many forms of erosion have shaped Chandor Chasma. There is evidence of wind and water erosion, as well as significant gravity driven mass wasting landslides.
Mass wasting features in Juventae Chasma, Mars. Introduction : We report mass-wasting features preserved as debris aprons from Juventae Chasma. Diverse lines of evidence and associated geomorphological features indicate that fluidized ice or water within the wall rocks of the chasma could be responsible for mobilizing the debris. Discussion : Amphitheatre-headed tributary canyons , which are formed due to ground water sapping, indicate that the same was responsible for wall-section collapse, although a structural control cannot be completely ruled out.
The emplacement of the mass wasting features preferentially at the mouths of amphitheatre-headed tributary canyons along with the rounded flow fronts of the debris suggest fluids may have played a vital role in their emplacement. The mass-wasting features in Juventae Chasma are unique compared to other landslides in Valles Marineris despite commonalities such as the radial furrows, fan-shaped outlines, overlapping aprons and overtopped obstacles.
The unique set of features and close association with amphitheatre-headed tributary canyons imply that the trigger of the landslides was not structural or tectonic but possibly weakness imparted by the presence of water or ice in the pore-spaces of the wall.
Craters with fluidized ejecta blankets and scalloped depressions in the surrounding plateau also support this. Moving into the central part of Ius Chasma, the canyon profile changes. What started as a large graben south of the main chasma wall, has widened to create a central high ridge separating the chasm into two parallel sections. This interior ridge is called Geryon Montes. The northern canyon wall is at the top of the image, including several tongue shaped landslide deposits.
The floor has been covered in deposits that may include landslide material and later materials such as air fall particles like dust and water lain layered deposits. Just to the top of the Montes are materials with different "colors". These are part of the layered materials inside the canyon. At the very bottom of the image a highly eroded landslide deposit exists. The materials on this side of Geryon Montes are at a higher elevation than the floor on the opposite side. The unusual texture of the canyon floor also points to layered materials that may have been laid down in standing water.
Today's image is just a bit further to the west of yesterday's. Here there are no dunes, but extensive outcrops of layered material. It is possible that these layered deposits were formed by sediments settling in a lake. This VIS image is located along the northern side of the chasma.
The linear features are on the surface of a large landslide. This region of Melas Chasma is covered by several very large landslide deposits. Hematite-bearing materials surrounding Candor Mensa in Candor Chasma, Mars: Implications for hematite origin and post-emplacement modification. The Valles Marineris canyon system on Mars is of enduring scientific interest in part due to the presence of interior mounds that contain extensive layering and water-altered minerals, such as crystalline gray hematite and hydrated sulfates.
The presence of hematite and hydrated sulfate minerals is important because their host rock lithologies provide information about past environments that may have supported liquid water and may have been habitable. This work further defines the association and relationship between hematite-bearing materials and low albedo presumably aeolian deposits and layered materials, identifies physical characteristics that are strongly correlated with the presence of hematite, and refines hypotheses for the origin and post-emplacement modification including transport of these hematite-bearing and associated materials.
There are only three regions surrounding Candor Mensa where hematite has been identified, even though morphologic properties are similar throughout the entire mensa.
The observations of hematite-bearing materials in this work support the hypothesis that hematite is eroding from a unit in the Candor Mensa interior layered deposits ILD and is being concentrated as a lag deposit adjacent to the lower layers of Candor Mensa and at the base in the form of dark aeolian material.
Due to the similar geologic context associated with hematite-bearing and ILD materials throughout the Valles Marineris canyon system, the insight gained from studying these. Light-Toned Layers in Tithonium Chasma. If Valles Marineris was located on Earth, at more than 4, kilometers long and kilometers wide, it would span across almost the entire United States.
Tithonium Chasma is approximately kilometers long. A "chasma," as defined by the International Astronomical Union, is an elongate, steep-sided depression.
The walls of canyons often contain bedrock exposing numerous layers. In some regions, light-toned layered deposits erode faster than the darker-toned ones. The layered deposits in the canyons are of great interest to scientists, as these exposures may shed light on past water activity on Mars.
Because sulfates generally form from water, the light-toned sulfate rich deposits in the canyons may contain traces of ancient life. The mid-section of this image is an excellent example of the numerous layered deposits, known as interior layered deposits.
The exact nature of their formation is still unclear. The Valles Marineris is a system of canyons located just south of the Martian equator. The system is about km long, and, if on earth, would extend all the way across the United States. The central individual troughs, generally 50 to km wide, merge into a depression as much as km wide.
In places the canyon floor reaches a depth of 10 km, 6 to 7 times deeper than the Grand Canyon. The geologic history of the central canyon system is complex: first the surface collapsed into a few deep depressions that later became filled with layered material, perhaps as lake deposits.
Then graben-forming faults cut across some of the older troughs thus widening existing troughs, breaching barriers between troughs, and forming additional ones.
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