Margaritifer Sinus Region
MC-19
Topographical Map of the Margaritifer Sinus Region with the location of the MER Opportunity Landing Site.
In part two of this Phase we start in the center of the Margaritifer Sinus Region in an area called the Margaritifer Terra Area.
Margaritifer Terra and Vicinity
At 240°E 21°S we come to Jones Crater.
Geologic Contacts in Jones Crater
Jones Crater is 94 km in diameter and is named after Sir Harold Spencer Jones KBE (29 March 1890 Kensington, London – 3 November 1960) who was an English astronomer.
Just to the east of Jones Crater is the Loire Valles at 18.11°S 343.3°E.
The Loire Valles
The Loire Valles is 720 km in length and is is named after the Loire River the longest river in France.
The outflow channel leading north from the Ladon Basin is the Morava Valles. It is located at 335°E 14°S.
Near the Mouth of Morava Valles
The Morava Valles is 325 km long and is named after the Morava (German: March, Hungarian: Morva) river in Central Europe. The Morava Valles leads to the Margaritifer Chaos. Morava Valles is an outflow channel for the Ladon Basin and discharged water towards the large regions of chaotic terrain near the head of Ares Valles. Because the valley emerges full bore from Ladon Basin (much like the Niagara river emerges from Lake Erie on the Earth), it has been hypothesized that it was formed when a lake overflowed the basin. There are numerous valleys, including the large Ladon Valles, that end along the margin of Ladon Basin. Some of the outcrops visible in this image and elsewhere in the basin show evidence of layering due to deposition of sediments.
Margaritifer Chaos Area
Layer Bedrock in Margaritifer Chaos
The formation of the large outflow channels on Mars have been attributed to catastrophic discharges of ground water. Many of the channels start in areas where the ground has apparently collapsed: the surface is now well below the surrounding undisturbed ground. Within the collapsed region, blocks of undisturbed material can often be seen and this has led to such regions being called chaotic terrain.
The area referred to as Aureum Chaos is located at 333 degrees East, 4.5 degrees South on the West side of the Margaritifer Chaos.
The Aureum Chaos
The Aureum Chaos is a rough, collapsed region in the Margaritifer Sinus Region (MC-19) portion of the planet Mars at approximately 4.5° south latitude and 333° East longitude. Located on the west side of the Margaritifer Chaos. It is 368 km across and was named after a classical albedo feature name. The classic name came from one of the first maps of Mars drawn by Schiaparelli who has been called the "Father of Mars." He called the feature "Aurea Cherso, which translates to the golden peninsula—an ancient name for Malaya. Aureum is the Latin word for gold. In chemistry, the symbol for gold is Au from gold's Latin name. In many places, the canyons of Aureum Chaos are about 1 km deep—a little more than half the depth of the Grand Canyon. But, Aureum Chaos covers an area about the size of the state of Alabama, almost 20 times larger than the Grand Canyon National Park. Some take places like this on Mars to be Martian underground cities. But this is not the case. The features that appear to rise between the blocks are actually channels running between the blocks. So this is a natural phenomena caused by the action of water draining out of the area. There still may be some water(ice) inside the blocks themselves.
Colorful Aureum Chaos
Following another channel leading to the northeast from Margaritifer Chaos we come to Ini Chaos which is centered at 2°S 343 E.
Proposed Landing Area in Iani Chaos, as seen by Themis
Iani Chaos is a minor canyon accounting for a portion of the extraterrestrial valley, Ares Vallis, of the Margaritifer Sinus Region of the planet Mars. This is the source region of Ares Vallis on Mars, where it is centered at approximately ~342°E, 2°S. The chaotic terrain is widely believed to have formed via the removal of subsurface water or ice, resulting in flooding at the surface, and the formation of Ares Vallis. Within Iani Chaos, deposited stratigraphically above the chaotic terrain, are smooth, low-slope, intermediate-to-light-toned deposits that are rich in a hydrated mineral that is most likely gypsum as well as hematite. Those two minerals are usually formed in connection with water.
In the northeastern corner of the Margaritifer Sinus Region we come to the Meridiani Planum which is part of the larger area of Arabia Terra that extends into the surrounding Regions as well.
Meridiani Planum
Meridiani Planum is a plain located 2 degrees south of Mars' equator (centered at 0.2°N 357.5°E), in the westernmost portion of Terra Meridiani. It hosts a rare occurrence of gray crystalline hematite. On Earth, hematite is often formed in hot springs or in standing pools of water; therefore, many scientists believe that the hematite at Meridiani Planum may be indicative of ancient hot springs or that the environment contained liquid water. The hematite is part of a layered sedimentary rock formation about 200 to 800 meters thick. Other features of Meridiani Planum include volcanic basalt and impact craters. Results from the Opportunity Rover indicate that its landing site was once saturated for a long period of time with liquid water, possibly of high salinity and acidity. Features that suggest this include cross-bedded sediments, the presence of many small spherical pebbles that appear to be concretions, vugs inside rocks, and the presence of large amounts of magnesium sulfate and other sulfate-rich minerals such as Jarosite.
The Landing of the Mars Rover Opportunity
The Rover landed in an impact crater which became known as Eagle Crater
Eagle Crater Rim
This high-resolution image captured by the Mars Exploration Rover Opportunity's panoramic camera highlights the puzzling rock outcropping that scientists were eagerly planning to investigate. At that time, Opportunity was on its lander facing northeast; the outcropping lies to the northwest. These layered rocks measure only 10 centimeters (4 inches) tall and were thought to be either volcanic ash deposits or sediments carried by water or wind. Data from the panoramic camera's near-infrared, blue and green filters were combined to create this approximate, true-color image. The interior of a crater surrounding the Mars Exploration Rover Opportunity at Meridiani Planum on Mars can be seen in this color image from the rover's panoramic camera. This is the darkest landing site ever visited by a spacecraft on Mars. The rim of the crater is approximately 10 meters (32 feet) from the rover. The crater is estimated to be 20 meters (65 feet) in diameter. Scientists are intrigued by the abundance of rock outcrops dispersed throughout the crater, as well as the crater's soil, which appears to be a mixture of coarse gray grains and fine reddish grains.
The rock "Berry Bowl".
Martian blueberries (hematite spheres) near Opportunity’s landing site.
Drawing showing how "blueberries" came to cover much of surface in Meridiani Planum.
Microscopic images of the soil taken by Opportunity revealed small spherically shaped granules. They were first seen on pictures taken on Sol 10, right after the rover drove from the lander onto Martian soil. On March 18 the results of the investigation of the area called "Berry Bowl" was announced. This site is a large rock with a small, bowl-shaped depression, in which a large number of spherules had accumulated. The MIMOS II Mössbauer spectrometer was used to analyze the depression and then the area of the rock right beside it. Any difference in the measured data was then attributed to the material in the spherules. A large difference in the obtained "spectra" was found. "This is the fingerprint of hematite, so they concluded that the major iron-bearing mineral in the berries was hematite," said Daniel Rodionov, a rover science team collaborator from the University of Mainz, Germany. This discovery seems to strengthen the conclusion, that spherules are concretions, grown in wet condition with dissolved iron.
Some of Mars as Seen by the Mars Opportunity Rover
Bedrock Minerals: Few rocks were visible on the surface where Opportunity landed, but bedrock that was exposed in craters was examined by the suit of instruments on the Rover. Bedrock rocks were found to be sedimentary rocks with a high concentration of sulfur in the form of calcium and magnesium sulfates. Some of the sulfates that may be present in bedrocks are kieserite, sulfate anhydrate, bassanite, hexahydrite, epsomite, and gypsum. Salts, such as halite, bischofite, antarcticite, bloedite, vanthoffite, or gluberite may also be present.
Opportunity Rover at Endeavor Crater
Endeavor Crater is located at 354.9°E 2.5°S. When Opportunity Rover traveled to the rim of Endeavour crater, it soon found a white vein that was later identified as being pure gypsum. It was formed when water carrying gypsum in solution deposited the mineral in a crack in the rock.
Endeavor Crater Western Rim HiRISE DTM
This digital terrain model covers the western rim of Endeavour Crater where the Mars Exploration Rover Opportunity has been investigating since 2011. It provides valuable topographic data that have been very useful in Opportunity mission planning.
Sub image of region of Exploration
For example, this sub image shows a northward perspective view of HiRISE and compositional data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) overlaid over the DTM of Endeavour Crater. This image shows where orbital data indicate possible clay (red), sulfate (green), and volcanic (blue) minerals are located, where the former two attest to the regions aqueous ancient past. Ongoing surface operations by Opportunity are attempting to reveal the geologic history at Endeavour crater.
“Heat Shield Rock” was the first meteorite ever identified on another planet, discovered by Opportunity
Opportunity Rover found meteorites just sitting on the plains. The first one analyzed with Opportunity’s instruments was called "Heat shield Rock," as it was found near where Opportunity’s heat shield landed. Examination with the Miniature Thermal Emission Spectrometer (Mini-TES), Mossbauer spectrometer, and APXS lead researchers to, classify it as an IAB meteorite. The APXS determined it was composed of 93% iron and 7% nickel.
The Mars Opportunity Rover remains active as of 2014, having already exceeded its planned 90 sol (Martian days) duration of activity by 9 years, 267 days (in Earth time). Opportunity has continued to move, gather scientific observations, and report back to Earth for over 40 times its designed lifespan. Mission highlights include the initial 90 sol mission, finding extra-Martian meteorites such as in the Meridiani Planum, and over two years studying Victoria crater. It survived dust-storms and reached Endeavour crater in 2011, which has been described as a "second landing site". As of January 7, 2014 the total odometry for the Mars Opportunity Rover is 24.07 miles (38.73 kilometers). It holds the distance record for the longest distance traveled on any planet thus far by a planetary rover.
Meridiani Planum is part of a larger area called Arabia Terra which covers the northeast corner of the Margaritifer Sinus Region.
Possible Rover Landing Site - Southwest Arabia Terra HiRISE DTM at 5.6°S 355°E.
Arabia Terra is a large upland region in the north of Mars in that lies mostly in the Arabia Region. It is densely cratered and heavily eroded. This battered topography indicates great age, and Arabia Terra is presumed to be one of the oldest terrains on the planet. It covers as much as 4,500 km (2,800 mi) at its longest extent.
Possible Cyclic Bedding in A Crater in Arabia Terra
Miyamoto Crater
Miyamoto Crater is located in southwest Meridiani Planum (and southwest of the Mars Exploration Rover Opportunity landing site). This image shows fairly smooth plains and some areas covered by wind streaks, suggesting that wind is an active process here, depositing surface material downwind in the form of streaks. This landing site is adjacent to the hematite-bearing plains unit where the Opportunity rover sits. The CRISM instrument has detected phyllosilicates (clay minerals) at this landing site, which scientists believe to have formed in the presence of water. The MSL rover would be able investigate the mineral diversity here, which includes phyllosilicates and sulfates. Of course the MSL landed somewhere else and this investigation has not happened yet. Miyamoto Crater is located at 2.8°S 353°E. It is 160 km in diameter.
The next feature we come to is Beer Crater located at 15°S 351.5°E.
The Floor of Beer Crater
This crater was named after German astronomer Wilhelm Beer. It is an ancient crater which is 90 kilometers diameter, located south of Meridiani Planum. The full-resolution color sample above shows fractured bedrock with dark sand filling low areas. The circular rocky features are probably eroded impact craters and the thin linear features are windblown deposits. The Aeolian (wind) erosion and modification of this ancient surface make it difficult to deduce how the rocks were initially emplaced, but the channeled rims suggest that these could be alluvial fans: deposits carried by flowing water.
Going further south we come to Peta Crater. It is located at 21°S 351° E.
Peta Crater as seen by Themis
Peta Crater is 80.5 km in diameter and is named after a Greece place name. Analysis of this image reveal characteristics, such as layers along the ridge walls in the center of the crater that would indicate that the ridge was deposited by flowing water. Rocks and boulders might be found eroding from the ridge, their size and shape offering clues to the strength of the ridge material.
Just to the southwest of Peta Crater is the Parana Valles at 23°S 350°E.
Parana Valles is a valley in the Margaritifer Sinus Region of Mars. It is 350 km long and was named after an ancient and modern name for a South American river (Brazil & Argentina). The low area between Parana Valles and Loire Vallis is believed to have once held a lake.
CTX context image for this image that was taken with HiRISE.
Note long ridge going across the image is probably an old stream. The box indicates the area for HiRISE image.
To the west of Parana Valles is Erythraeum Chaos at 22°S 347.5°E.
Erythaeum Chaos As seen by Themis
Erythraeum Chaos is 149 km in diameter and is further proof that this area contained a great deal of water.
To the southeast of Erythraeum Chaos is Novara Crater at 25°S and 249°E.
Possible Phyllosilicate on Floor of Novara Crater
Novara Crater is 87 miles in diameter and is named after and Italy place name.
On the eastern border of the Margaritifer Sinus Region between 22-26.5°S is the western half of Newcomb Crater.
Newcomb Crater
Newcomb Crater is 252 km in diameter and is named after Simon Newcomb (March 12, 1835 – July 11, 1909) who was a Canadian-American astronomer and mathematician.
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