Arabia Region
MC-12
Topographical Map of the Arabia Region
This Region contains part of the classic area of Mars known as Arabia. It lies on the boundary between the young northern plains and the old southern highlands. The Arabia Region covers the area from 315° to 360° west longitude and 0° to 30° north latitude.
Image of the Arabia Region
The surface of the Arabia Region appears to be very old because it has a high density of craters, but it is not near as high in elevation as typical old surfaces. On Mars the oldest areas contain the most craters; the oldest period is called the Noachian after the Region Noachis. The Arabia Region contains many buttes and ridges.
Layered butte in Arabia Terra, as seen by HiRISE under HI Wish program. Location is 29.7 N and 6.4 E.
Some believe that during certain climate changes an ice-dust layer was deposited; later, parts were eroded to form buttes. Some outflow channels are found in Arabia, namely Naktong Vallis, Locras Valles, Indus Vallis, Scamander Vallis, and Cusus Valles. The Arabia Region has many unnamed craters and a very high crater population some of them are very large.
Layers in Arabia Terra as seen by HiRISE under HI Wish program
Starting from the northeast corner of the Region we enter into the Arabia Terra area which covers about a third of the Arabia Region-especially in the western part. 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, centered roughly at 19.79°N 30°E with its eastern and southern regions rising 4 km (13,000 ft) above the north-west. Alongside its many craters, canyons wind through the Arabia Terra, many emptying into the large northern lowlands of the planet, which borders Arabia Terra to the north.
Northern Arabia Terra
The first crater of any consequence that we come to is Maggini Crater. It is located at 28.0°N 350.6°W and is 143 km in diameter.
.Maggini Crater
Mentore Maggini (February 6, 1890 – May 8, 1941) was an Italian astronomer. He was director of the Collurania Observatory and is best known for his maps of Mars and the work on binary stars. This crater on Mars was named in his honor.
Going further south we come to Gill Crater.
Layers in Gill Crater wall, as seen by HiRISE under HI Wish program. Location is 16.5 N and 5.4 E.
Layers in mesa, as seen by HiRISE under HI Wish program also in Gill Crater.
Meridiani Planum in Southwest Arabia Region corner on the Equator
It is believed a source of Martian Methane comes from this region. One study with the Planetary Fourier Spectrometer in the Mars Express spacecraft found possible methane in three areas of Mars, one of which was in the Arabia Region. One possible source of methane is from the metabolism of living bacteria. However, a recent study indicates that to match the observations of methane, there must be something that quickly destroys the gas, otherwise it would be spread all through the atmosphere instead of being concentrated in just a few locations. Its destruction would be caused by the sun’s radiation and cosmic rays. There may be something in the soil that oxidizes the gas before it has a chance to spread which seems doubtful Life forms could be producing this gas as a by- product of their metabolism under the ground.
Martian Methane Production
Trace amounts of methane in the atmosphere of Mars were discovered in 2003 and verified in 2004. As methane is an unstable gas, its presence indicates that there must be an active source on the planet in order to keep such levels in the atmosphere. It is estimated that Mars must produce 270 tons of methane a year, but asteroid impacts are believed to account for only 0.8% of the total methane production. Although geologic sources of methane such as serpentinization are possible, the lack of current volcanism, hydrothermal activity or hotspots are not favorable for this form of geologic methane. It has been suggested that the methane was produced by chemical reactions in meteorites, driven by the intense heat during entry through the atmosphere. Although research published in December 2009 ruled out this possibility, research published in 2012 suggest that a source may be organic compounds on meteorites that are converted to methane by ultraviolet radiation. The existence of life in the form of microorganisms such as methanogens is among the possible, but as yet unproven sources. If microscopic Martian life is producing the methane, it likely resides far below the surface, where it is still warm enough for liquid water to exist. Since the 2003 discovery of methane in the atmosphere, some scientists have been designing models and in vitro experiments testing growth of methanogenic bacteria on simulated Martian soil, where all four methanogen strains tested produced substantial levels of methane, even in the presence of 1.0wt% perchlorate salt. The results reported indicate that the perchlorates discovered by the Phoenix Lander would not rule out the possible presence of methanogens on Mars. In June 2012, scientists reported that measuring the ratio of hydrogen and methane levels on Mars may help determine the likelihood of life on Mars. According to the scientists, "...low H2/CH4 ratios (less than approximately 40) indicate that life is likely present and active." Other scientists have recently reported methods of detecting hydrogen and methane in other extraterrestrial atmospheres as well.
Next we head to the northeast to Capen Crater. The Mars Reconnaissance Orbiter showed deformation bands in Capen Crater, located in the Arabia Region. Deformation bands are small faults with very small displacements. They often proceed large faults. They develop in porous rocks, like sandstone. They can restrict and/or change the flow of fluids like water and oil. The bands on Mars are a few meters wide and up to a few kilometers long. They are caused by the compression or stretching of underground layers. Erosion of overlying layers make them visible at the surface. Capen Crater was unnamed before the discovery of deformation bands. It was named for Charles Capen, who studied Mars at JPL's Table Mountain Observatory in California and at Lowell Observatory in Arizona.
The group of lines running up and down in the image are believed to be deformation bands. They can be thought of as small faults.
Capen Crater is located at 6.57°N 345.73°W. and it is 70 km in diameter. A large basin, maybe from an impact, was produced early in Martian history. It was so early that Mars still had a magnetic field generated by movements in a liquid core. The present day Arabia Region possesses a remnant magnetism from that ancient era. Therefore it might be possible for atmospheric gases to exist in a higher concentration in this area in a elongated bubble due to this remnant of magnetism in this area.
Going to the northeast we come to Henry Crater. Henry Crater is a large crater in the Arabia quadrangle of Mars, located at 10.9° north latitude and 336.7° west longitude. It is 171 kilometers (106 mi) in diameter and was named after the brothers Paul-Pierre Henry and Mathieu-Prosper Henry, both of whom were French telescope makers and astronomers. Mounds in craters like Henry are formed by the erosion of layers that were deposited after the impact.
Mound in Henry Crater
To the north and west of Henry crater we enter the southern part of Arabia Terra.
Complex system of ridges in Arabia Terra
Southern Arabia Terra
Northeast of Henry Crater is Pasteur Crater also in the Arabia Region of Mars, located at 19.4° north latitude and 335.5° west longitude. It is 113 kilometers (70 mi) in diameter and was named after Louis Pasteur, a French chemist. Dark sand dunes are clustered in the southwest of the crater. The orientation of the Barchan dunes suggest that they were generated by northeasterly winds. The source of the dune's sand appears to be local. Upwind of the dunes there is a small crater, Euphrates, within Pasteur crater that may have excavated sediments. The dark sediments have formed a patch at Euphrates' base. HiRISE imagery of the intracrater dunes within Pasteur crater over 1 Martian year indicate that the dunes are active with sand movement in a southwesterly direction.
Erosion in Pasteur Crater
Going to the northeast of that Crater we come to the Cassini Crater and just on it’s northern rim is Luzin Crater. Cassini Crater on Mars is named in honor of the Italian astronomer Giovanni Cassini. The crater is approximately 415 km in diameter and can be found at 327.9°W and 23.8°N. It is in the Arabia Region of Mars. Recent research leads scientists to believe that some of the craters in Arabia may have held huge lakes. Cassini Crater probably once was full of water since its rim seems to have been breached by the waters. Both inflow and outflow channels have been observed on its rim. The lake would have contained more water than Earth's Lake Baikal, our largest freshwater lake by volume.
Layers in the Cassini Crater Floor
Crater on the floor of Cassini crater, as seen by HI rise. The location is 24 degrees north latitude and 327.9 degrees west longitude.
Just to the southeast of Cassini Crater is the Indus Vallis Location is 18.8 degrees north and 39.8 degrees East.
Indus Vallis
Indus Vallis is a river valley in the Arabia Region of Mars. It is 307 km long and was named after the ancient and modern name for a river in Pakistan.
Geological History of the Arabia Region:
Recent studies, reported in the journal Icarus, have suggested that the area underwent several phases in its formation:
- A large basin, maybe from an impact, was produced early in Martian history. It was so early that Mars still had a magnetic field generated by movements in a liquid core. Present day Arabia possesses a remnant magnetism from that ancient era.
- Sediments flowed into the basin. Water entered the basin.
- Because Tharsis, on the other side of Mars, became so massive, the area around Arabia was pushed out. As it bulged upward, there was increased erosion which exposed old layers. When portions of a planet that can be subject to erosion rise, there is greatly increased erosion; Earth's Grand Canyon became very deep because it was eroded into a high plateau.
- Over the following 4 billion years, the area was modified by various geological processes. Central peaks and ejecta shapes indicate that parts of Arabia are still water enriched.
Continuing on a more southerly route from Cassini we come to a bigger valley the Scamander Vallis.
Northeast Extent of Scamander Vallis
Following Scamander Vallis southward we enter the Terra Sabaea area. The Terra Sabaea area is the uplands of the Arabia Region and occupy almost a third of the Arabia Region mostly in the southeast part. Almost ESE of Scamander Vallis is Tikhonravov Crater.
Location is 12.8 N and 34.9 E. Pedestal craters and layers in Tikhonravov Crater. in Arabia Region, as seen by Mars Global Surveyor (MGS), under the MOC Public Targeting Program. Layers may form from volcanoes, the wind, or by deposition under water. Some researchers believe this crater once held a massive lake.
How Pedestal Craters are formed
Tikhonravov Crater: is a large, eroded crater in the Arabia Region of Mars. It is 386.0 kilometers (240 mi) in diameter and was named after Mikhail Tikhonravov, a Russian rocket scientist. Tikonravov is believed to have once held a giant lake that drained into the 4500 km long Naktong-Scamander-Mamers lake-chain system. An inflow and outflow channel has been identified. Recent research leads scientists to believe that some of the craters in Arabia may have held huge lakes. Cassini Crater and Tikonravov Crater probably once were full of water since their rims seem to have been breached by water. Both inflow and outflow channels have been observed on their rims. Each of these lakes would have contained more water than Earth's Lake Baikal, our largest freshwater lake by volume. The watersheds for lakes in Arabia seem to be too small to gather enough water by precipitation alone; therefore it is thought that much of their water came from groundwater.
Continuing southward into Terra Sabaea we follow the Scamander Vallis into Arago Crater.
Elevation Map of Arago Crater
The crater’s location is 11.5°N 28.6°E. diameter 145 km. Named after Dominique F. Arago a French astronomer (1786-1853).
From there we follow another river valley southward the Naktong Vallis. It is an ancient river valley in the Arabia Region of Mars, located at 5.3 degrees north latitude and 327.1 degrees west longitude. It is 494 km long and was named after a river in Korea. Naktong Vallis is part of the Naktong/Scamander/Mamers Valles lake-chain system that is comparable in length of Earth's largest system, like the Missouri-Mississippi Rivers.
Naktong Vallis
East of Naktong Vallis at about 3°N is Janssen Crater.
Rock Outcrop in Janssen Crater
Janssen Crater is located at 3.3°N and 38.2°E. Named after Pierre, Jules Janssen a Mathematician and Physicist Born in Paris, in February 22nd 1824, and died in Meudon, in December 23rd 1907.
Terraforming Mars Phase 2:
The Surface Gravity & Magnetosphere on Mars is 38% of that on Earth. It is not known if this is enough to prevent the health problems associated with weightlessness. Additionally, the low gravity (and thus low escape velocity) of Mars may render it more difficult for the planet to retain an atmosphere when compared to the more massive Earth and Venus. Earth and Venus are both able to sustain thick atmospheres, even though they experience more of the solar wind that is believed to strip away planetary volatiles (the atmosphere). Continuing sources of atmospheric gases on Mars might therefore be required to ensure that an atmosphere sufficiently dense for humans is sustained in the long term. Mars lacks a magnetosphere, which poses challenges for mitigating solar radiation and retaining atmosphere. It is believed that fields detected on the planet are remnants of a magnetosphere that collapsed early in the planet's history. The lack of a magnetosphere is thought to be one reason for the planet's thin atmosphere. Solar wind-induced ejection of Martian atmospheric atoms has been detected by Mars-orbiting probes. Venus, however, clearly demonstrates that the lack of a magnetosphere does not preclude a dense atmosphere. Earth abounds with water because its ionosphere is permeated with a magnetosphere. The hydrogen ions present in its ionosphere move very fast due to their small mass, but they cannot escape to outer space because their trajectories are deflected by the magnetic field. Venus has a dense atmosphere, but only traces of water vapor (20 ppm) because it has no magnetic field. The Martian atmosphere also loses water to space. Earth's ozone layer provides additional protection. Ultraviolet light is blocked before it can dissociate water into hydrogen and oxygen. Since little water vapor rises above the troposphere and the ozone layer is in the upper stratosphere, little water is dissociated into hydrogen and oxygen. The Earth's magnetic field is 31 µT. Mars would require a similar magnetic field intensity to similarly offset the effects of the solar wind at a distance farther from the Sun. The technology for inducing a planetary scale magnetic field does not currently exist.
The Dream Phase 2 …………..
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