Margaritifer Sinus Region
MC-19
The Margaritifer Sinus Region covers the area from 0° to 45° west longitude and 0° to 30° south latitude on Mars. This Region shows many signs of past water with evidence of lakes, deltas, ancient rivers, inverted channels, and chaos regions that released water. Margaritifer Sinus contains some of the longest lake-chain systems on Mars, perhaps because of a wetter climate, more groundwater, or some of each factor.
Image of Margaritifer Sinus Region
Beginning with this Phase we return to our north to south and south to north orientation in this survey. We enter this Region from the northwest corner headed south but while making our way eastward towards the next Region.
The first area we come into is the Xanthe Terra Area. We have been in this Area before. You will note that there are many Chaos areas in the Margaritifer Sinus Region a sure sign that water was once in abundance here.
Xanthe Terra
Next we come to Ravi Vallis at 1.5°S and stretching from 316-320°E.
Ravi Vallis is one of the shortest, yet most dramatic of Martian outflow channels
Ravi Vallis was probably formed when catastrophic floods came out of the ground to the right (chaotic terrain). Ravi Vallis is located in Margaritifer Sinus Region. It is 205.5 km long and was named after the Ravi River, an ancient Pakistani River. Ravi Vallis is an ancient outflow channel in the Margaritifer Sinus Region.
Along the northern border in this area is the Hydroates Chaos stretching from 322-328°E.
Hydroates Chaos on the northern border of the Margaritifer Sinus Region
At 4°S 326 E. we come to Balboa Crater.
Balboa Crater and Vicinity
Balboa Crater is 23 km in diameter and is named after a Panama place name.
After this to the west we come to Chinju Crater at 4.5 S and 318°E.
Chinju Crater is the large Crater in the center of the Picture
Chinju Crater is 66 km in diameter and is named after a South Korean place name. Heading south we cross Capri Chasma then the Eos Mensa and finally the Eos Chasma all of which is now taking a turn to the north into the Aurorae Chaos Area.
Aurorae Chaos and channel fork area
Then from there it forks of into two channels heading north. One going into the Hydroates Chaos Region and into the next Region to the north. The other taking a more northeasterly course ending in the Aureum Chaos.
Eos Chasma is a Chasma in the southern part of the Valles Marineris canyon system of the Margaritifer Sinus Region of the planet Mars. Eos Chasma’s western floor is mainly composed of an etched massive material composed of either volcanic or Aeolian deposits later eroded by the Martian wind. The eastern end of the Eos Chasma has a large area of streamlined bars and longitudinal striations. This is interpreted to be stream-carved plateau deposits and material transported and deposited by flowing fluid. In September 2005, Vicky Hamilton of the University of Hawaii at Manoa presented an analysis of the origin of the meteorite ALH 84001 using data from the Mars Global Surveyor and Mars Odyssey spacecraft orbiting Mars. According to the analysis, Eos Chasma in the Valles Marineris canyon appears to be the source of the meteorite. NASA maintains a catalog of 34 Mars meteorites. These assets are highly valuable since they are the only physical samples available of Mars. Studies conducted by NASA's Johnson Space Center show that at least three of the meteorites contain potential evidence of past life on Mars, in the form of microscopic structures resembling fossilized bacteria (so-called biomorphs). Although the scientific evidence collected is reliable, its interpretation varies. To date, none of the original lines of scientific evidence for the hypothesis that the biomorphs are of exobiological origin (the so-called biogenic hypothesis) have been either discredited or positively ascribed to non-biological explanations. Over the past few decades, seven criteria have been established for the recognition of past life within terrestrial geologic samples. Those criteria are:
1. Is the geologic context of the sample compatible with past life?
2. Is the age of the sample and its stratigraphic location compatible with possible life
3. Does the sample contain evidence of cellular morphology and colonies?
4. Is there any evidence of biomaterials showing chemical or mineral disequilibria?
5. Is there any evidence of stable isotope patterns unique to biology?
6. Are there any organic biomarkers present?
7. Are the features indigenous to the sample?
Allan Hills 84001 (commonly abbreviated ALH 84001) is a meteorite that was found in Allan Hills, Antarctica on December 27, 1984 by a team of U.S. meteorite hunters from the ANSMET project. Like other members of the group of SNCs (Shergottite, Nakhlite, Chassignite), ALH 84001 is thought to be from Mars. However, it does not fit into any of the previously discovered SNC groups. On discovery, its mass was 1.93 kilograms (4.3 lb.). It made its way into headlines worldwide in 1996 when scientists announced that it might contain evidence for microscopic fossils of Martian bacteria based on carbonate globules observed.
Allan Hills 84001 Whole Meteorite
This rock is theorized to be one of the oldest pieces of the solar system, proposed to have crystallized from molten rock 4.091 billion years ago. Based on chemical analyses, it is thought to have originated on Mars from a period when liquid water — a requirement for the presence of life — probably existed on the now barren planet's surface.
The theory holds that ALH 84001 was shocked and broken by one or more meteorite impacts on the surface of Mars some 3.9 to 4.0 billion years ago, but remained on the planet. It was later blasted off from the surface in a separate impact about 15 million years ago and impacted Earth roughly 13,000 years ago. These dates were established by a variety of radiometric dating techniques, including Samarium-Neodymium (Sm-Nd), Rubidium-Strontium (Rb-Sr), Potassium-Argon (K-Ar), and Carbon-14. Under the scanning electron microscope structures were revealed that some scientists interpreted as fossils of bacteria-like life forms. The structures found on ALH 84001 are 20-100 nanometers in diameter, similar in size to theoretical nanobacteria, but smaller than any known cellular life at the time of their discovery. If the structures are in fact fossilized life forms, as proposed by the so-called biogenic hypothesis of their formation, they would be the first solid evidence of the existence of extraterrestrial life, aside from the chance of their origin being terrestrial contamination (from Antarctica). It is really not certain, in my opinion, where any of these rocks come from. All 34 rocks are believed to be meteorites that come from Mars. ALH84001 is believed to be from this location but with doubt due to the way they discovered its point of origin. I would think that after being under the ice pack 13,000 years it would be kind of hard to come to that conclusion that this meteorite came from Mars. But many scientists insist that it comes from that planet. My question then is what is the criteria that makes a meteorite a Martian meteorite ? We have not been able to bring samples back from the planet yet-so how could they have come to this conclusion ? There is a lot of chemistry involved here and if they are trying to reproduce it in a lab I still don’t see how they could be completely correct. The only bacterial life forms we know about for certain is on Earth. Life may have taken a different direction (and probably did) on Mars. Anyway it is interesting to note that they have found a place of origin for this particular meteorite- Eos Chasma.
Continuing southward we come into the Noachis Terra Area again which is bordered on the east side in the north by the Margaritifer Terra until about 20°S where it continues eastward along the southern border of the Margaritifer Sinus Region.
Valley in Northern Noachis Terra
Just southeast of Eos Chasma is Osuga Valles at 321°E 16°S.
Chaos and Outflow Channel Floor Transition in Osuga Valles
Osuga Valles is 185 km in length and is named after the Osuga River in Russia.
Following this we come to the biggest Crater in the area Vinogradov Crater.
Vinogradov Crater
Vinogradov Crater is located at 322°E 20°S. It is 223.5 km in diameter and is named after Alexander Pavlovich Vinogradov (August 21, 1895, Petretsovo, Yaroslavl Oblast - November 16, 1975, Moscow)who was a Soviet geochemist, and academician.
Next we come to the Arda Valles located at 328°E 20.5°S.
Ancient Bedro
Ancient Bedrock Eroded by Arda Valles
Arda Valles is 186 km in length and is named after the Arda River, that is a 290 km long river in Bulgaria and Greece.
Eberswalde Crater lies just to the north of Holden Crater, a large crater that may have been a lake. The 65.3-km-diameter crater, centered at 24°S, 326.5 E, is named after the German town of the same name, in accordance with the International Astronomical Union's rules for planetary nomenclature.
Fossilized delta in Eberswalde crater
The crater contains inverted relief, an exhumed delta formed by the flow of a liquid, most likely water. The series of valleys leading into the delta "drain" an area of approximately 4000 km². The surface area of the delta is 115 km², measuring 13 km by 11 km.
Flyover of Eberswalde Crater
The first part of the video was shot in NASA colors, these colors are used to bring out terrain features and chemistry not seen with a normal camera. The second part of the video even though an animation is the true color of the area like it was taken with a normal camera.
Delta Structure in Eberswalde Crater HiRISE DTM 23°S 326°E.
Potential MSL Landing Site in Eberswalde Crater HiRISE DTM 24°S 326°E
Moving on from there a short distance to the southwest we come to Holden Crater at 24°S 326°E.
Flying over Western Holden Crater
Several sites in the Margaritifer Sinus Region had been proposed as areas to send NASA's next major Mars rover, the Mars Science Laboratory MSL (Now on Mars commonly known as the Curiosity rover). Both Holden Crater and Eberswalde Crater made the cut to be among the top four. Miyamoto Crater was in the top 7 sites chosen. Holden Crater is believed to have once been a lake. Actually, it is now believed that it held two lakes. The first was longer lived and was formed from drainage within the crater and precipitation. The last lake began when water dammed up and the Uzboi Vallis broke through a divide, then rapidly drained into Holden Crater. Because there are rocks meters in diameter on the crater floor, it is thought it was caused be a powerful flood when the water flowed into the crater.
HiRISE image of Breccia in Holden crater.
This HiRISE image covers the southwest portion of the terraces and floor of Holden Crater situated in southwest Margaritifer Terra Area. This HiRISE sub-frame shows the most clearly-evident image of a megabreccia on Mars. Breccia is a rock typically consisting of rock fragments of various sizes and shapes that have been broken, tumbled and cemented together in sudden geologic event (e.g., a landslide, a flashflood or even an impact-cratering event). If it were not for the dark sandy dunes dispersed through out the sub-image, this image could easily fool an expert into thinking that this image is actually a photograph of a hand sample of an impact breccia. The prefix "mega" implies that the breccia in the sub-image consists of clasts, or rock fragments, that are typically larger than a large house or a building. The rectangular megaclast near the center of the image is a colossal 50 x 25 meters (~150 X 75 feet). As mentioned in the transition image caption for Holden crater, the crater likely experienced extensive modification by running water, which is supported by observations of drainage and deposition into the crater from a large channel (Uzboi Valles) breaching Holden Crater’s southwest rim. While it is possible that the megabreccia formed from a catastrophic release of water into the crater, a more likely possibility is that it formed from the impact that created the approx. 150 km-in-diameter Holden crater.
Candidate MSL Landing Site in Holden Crater HiRISE DTM 26°S 325°E.
At 27.5°S 315°E Nirgal Valles enters the Margaritifer Sinus Region from our last Region and runs into the Uzbol Vallis at 30°S 322.3°E as it goes into the next Region to the south.
Nirgal Vallis Tributaries
Nirgal Valles is one of the longest valley networks on Mars. It is so large that it is found on three different Regions. Scientists are not sure about how all the ancient river valleys were formed. There is evidence that instead of rain or snow, the water that formed the valleys originated under ground. One mechanism that has been advanced is sapping. In this case, the ground just gives away as water comes out. Sapping is common in some desert areas in America's Southwest. It forms alcoves and stubby tributaries; these features are visible in the pictures of Nirgal Vallis taken with Mars Odyssey's THEMIS.
To the east of Holden Crater is Ostrov Crater at 27°S 332°E.
Ostrov Crater
Ostrov Crater is 73 km in diameter and is named after a Russian place name. Large alluvial fans in Martian craters were supplied mostly by erosion of deep valleys in the crater rims, such as the ones that surround Ostrov crater . Most of the floor of this crater is covered with large alluvial fans.
To the northeast of Ostrov Crater we come to Kasimov Crater at 25°S 327.5°E.
River Channels Inside Kasimov Crater
Kasimov Crater is 91.3 km in diameter and is named after a Russian place name.
Just to the northeast at a short distance is Moroz Crater located at 25°S 339.5°E.
Moroz Crater is the crater located in the center of this Picture
Moroz Crater is named after Vasily Ivanovich Moroz; a Russian planetary scientist (1931–2004).
Going west from there past Kasimov Crater we come to Chekalin Crater at 26 °S 335.5 °E.
Crater in Center of Picture is Chekalin Crater
If you compare the last two images you can see how close these craters are to each other. Moroz is a round crater and Chekalin looks like it is composed of two craters together one big and one small. Chekalin Crater is 89 km in diameter and is named after a Turkmenistan place name.
Layers Exposed Near the Mouth of Ladon Valles
This image crosses the mouth of Ladon Valles where it enters into the Ladon Basin in the Margaritifer Terra Area. Ladon Valles is an outflow channel forming a segment of a larger system that heads in Argyre basin to the south and eventually links up with the larger Ares Valles outflow channel to the north. Water flowing out of Ladon Valles appears to have ponded within Ladon basin, as evidenced by the numerous exposed layers. It is possible that these layers are exposed as a result of late flow down Ladon Valles that occurred after Holden Crater formed to the southwest. This late flow may have eroded the pre-existing layers deposited by prior flow. Ladon Valles is a river valley lying within the Margaritifer Sinus Region of the planet Mars located at 22.6° South and 330-332° East. It is 278 km long and was named after an ancient name for a Greek river. It has been argued that Uzboi, Ladon, Margaritifer, and Ares Valles, although now separated by large craters, once comprised a single outflow channel flowing north into the Chryse Planitia. The source of this outflow has been suggested as overflow from the Argyre crater, formerly filled to the brim as a lake by channels (Surius, Dzigai, and Palacopus Valles) draining down from the south pole. If real, the full length of this drainage system would be over 8000 km, the longest known drainage path in the solar system.
Proposed Future Landing Site in Ladon Valles Basin
The area known as the Ladon Basin is a the landscape feature is 440 kilometers (273.4 miles) across and between 3000-4000 meters deep. The double interconnected impact craters Sigli and Shambe are the primary points of attraction , as are their cracked floors. At this point, planetary scientists are not exactly sure as to what exactly caused this extensive fracturing in the basin.
Sediments and Troughs in Ladon Basin
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