Monday, November 18, 2013

Small Pale Red Planet Issue 2 Phase 9


The Elysium Region



The Elysium Region covers the area 180° to 225° west longitude and 0° to 30° north latitude on Mars. It contains the major volcanoes named Elysium Mons and Albor Tholus and river valleys--one of which, Athabasca Valles may be one of the youngest on Mars. On the east side is the interesting elongated depression called Orcus Patera.



Topographical Map of the Elysium Region

The Elysium quadrangle contains the volcanoes Elysium Mons and Albor Tholus. As a result much of this area is covered with lava flows, some can even be shown approaching, then stopping upon reaching higher ground.  Sometimes when lava flows the top cools quickly into a solid crust. However, the lava below often still flows, this action breaks up the top layer making for very rough terrain.


Image of the Elysium Region

Some of the valleys in the Elysium quadrangle seem to start from grabens. Granicus Vallis and Tinjar Vallis begin at a graben that lies just to the west of Elysium Mons. Certain observations suggest that they may have been the location of lahars (mudflows). The graben may have formed because of volcanic dikes. Heat from the dikes would have melted a great deal of ice. Two valleys, Hephaestus Fossae and Hebrus Valles, have sections that join and branch at high angles.  Starting at the northeast corner of the Elysium Region we come to a continuation of the Granicus Vallis.


Depression at Eastern end of Granicus Valles

The location as seen by HiRISE here is at 25°N 138°E.

Next we come to the Elysium Fossae.  The Elysium Fossae are a group of large troughs in the Elysium Region of Mars at 24.8° north latitude and 133.7° east longitude. They are about 1,175 km long and are named after a classical albedo feature name. The Elysium Fossae begins where the Granicus Valles end.


Location where the Granicus Valles and Elysium Fossae Meet

The Elysium Fossae is a large trough in the Elysium Region of Mars at 24.8° north latitude and 213.7° west longitude. It is about 1,175 km long and is named after a classical albedo feature name.  Elysium Fossae contains layers, also called strata. Many places on Mars show rocks arranged in layers. Sometimes the layers are of different colors. Light-toned rocks on Mars have been associated with hydrated minerals like sulfates. The Mars Rover Opportunity examined such layers close-up with several instruments. Some layers are probably made up of fine particles because they seem to break up into fine dust. Other layers break up into large boulders so they are probably much harder. Basalt, a volcanic rock, is thought to be in the layers that form boulders. Basalt has been identified on Mars in many places.  Instruments on orbiting spacecraft have detected clay (also called phyllosilicates) in some layers. Scientists are excited about finding hydrated minerals such as sulfates and clays on Mars because they are usually formed in the presence of water. Places that contain clays and/or other hydrated minerals would be good places to look for evidence of life.


Craters and Valleys in Elysium Fossae

This HiRISE image covers a small portion of the Elysium Fossae fracture system extending to the northeast from the giant Elysium Mons volcano.  The relative roles of tectonics (motion along faults), volcanism, and water remain puzzling. The large crater just north of the center of the HiRISE image appears to have formed by collapse, not by a meteorite impact. Had it been an impact crater, we would see a blanket of material (ejecta) that had been thrown out of the crater.  In general, this image demonstrates that this area has a similar stack of materials as other parts of the giant volcanoes on Mars. The deepest exposed material appears to be a stack of lava flows that produce thick layers that shed boulders. Above is a layer of weak material, possibly wind blown dust. Interestingly, in some areas (especially in the northern part of this image) there are thin, harder layers, more resistant to erosion, within the generally weak and easily eroded surface layer. These resistant layers seem to be too thin to be lava flows, and may indicate that some other process has hardened or cemented (indurated) portions of the weak material.

As we head  southward we pass the western lava fields that come from the Elysium Mons.  Much of the terrain to the west of this giant volcano has been affected by its past activity.  We  come to an area that is crisscrossed with fissures and channels called the Hyblaeus Fossae that leads to the Hyblaeus Catena.


Knobs West of Hyblaeus Fossae

To the east  is Hyblaeus Catena  from there the Hyblaeus Chasma crosses Elysium Chasma.


Locations of all three areas mentioned above

The Hyblaeus Catena is located at 21.5°N 141°E     and the Hyblaeus Chasma from 22-23°N by 141-142°E.  The Elysium Chasma stretches from 21-25°N by141-143°E.  At about 22.3 °N on this map on the other side of the Elysium Chasma we come to our next feature the Stura Vallis.


Stura Vallis, as seen by HiRISE. Location is 22.8 degrees north latitude and 142.8 degrees east longitude.

The Stura Vallis is an ancient river valley in the Elysium Region of Mars. It is 75 km long and was named after a classical river east of Rome, Italy.

Directly south of the Elysium Chasma  is Eddie Crater.


Central Peak of Eddie Crater

Eddie Crater: is a crater in the Elysium Region of Mars at 12.3° north latitude and 142° East longitude. It is 89 km in diameter and was named after Lindsay Eddie, a South African astronomer (1845–1913).

South of Eddie Crater on the Equator is Aeolis Planum a plateau extending from the Region from south of the Equator,  located at 5-0°N and 139-147.5°E.

Ridges in Aeolis Planum

Like the Utopia Planitia to the north the Elysium Planitia covers all of the southern parts of the Elysium Region   Unlike Earth, Mars is no longer protected by a global magnetic field or thick atmosphere. As a result, the planet has been vulnerable to radiation from space for billions of years.  "Even the hardiest cells we know of could not possibly survive the cosmic radiation near the surface of Mars for that long," said  Lewis Dartnell of University College London.  Dartnell and his lab developed a radiation dose model that calculates how much solar and galactic radiation Mars is subjected to. They tested three surface soil scenarios and calculated particle energies and radiation doses on the surface and at various depths underground. From this, they calculated the length of time that the hardiest known cells on Earth could survive. The team believes a good place to look for living cells on the red planet is in ice from a frozen sea recently discovered on the Elysium Planitia. Scientists think the sea formed only within the last five million years. "That's very, very recent, five million years ago is yesterday in terms of geology." The researchers estimate that life could survive for long periods of time about 8 yards (7.5 meters) beneath Elysium's ice. However, this is still beyond the range of any currently planned missions.. The only mission that will come close, Dartnell said, is ExoMars, a European rover slated for launch in 2013. ExoMars will be equipped with a drill that can dig about 6.5 feet (2 meters) for samples.  However, this is something a manned mission would be able to do better.  Methane has been detected in three areas on Mars; one of which is in the Elysium Region. This is exciting because one possible source of methane is from the metabolism of living bacteria.  So all the outward positive evidence is present there.

Lave Flows on the Equator in the Elysium Region

Located a few km to the east at 149°E is the Aeolis Serpens a river bed located between the Aeolis Planum and the Zeyphria Planum.  It originates south of the Elysium Region in the Aeolis Region to the south of the Equator.


Aeolis Serpens River bed in center of image

Going north from there we come to the Cerberus Palus. It is a plain in the Elysium Region of Mars, located at 5.8° North and 148.2° East. It is 480 km across and was named after a classical albedo feature. Terrain in this region has been shown to contain spiral-shaped geological features.


Blocks in  Cerberus Palus, as seen by HiRISE. Location is 7.8 North and 149.4 East.

The Cerberus Palus Area

Going north from there we cross into the Elysium Fossae again and the Elysium Catena at 17°N 150°E just south of the Volcano Albor Tholus. Then we come to the Albor Fossae at the base of the Volcano.

The Elysium Fossae in The Elysium Region is home to large troughs (long narrow depressions) called fossae in the geographical language used for Mars. Troughs are created when the crust is stretched until it breaks. The stretching can be due to the large weight of a nearby volcano. Fossae/pit craters are common near volcanoes in the Tharsis and Elysium system of volcanoes. A trough often has two breaks with a middle section moving down, leaving steep cliffs along the sides; such a trough is called a graben.


Troughs to the east of Albor Tholus, as seen by HiRISE under the HI Wish program.


Albor Tholus and Recent Activity

Albor Tholus is an extinct volcano  on Mars. It lies southeast of the neighboring large volcano Elysium Mons. Albor Tholus is 4.5 kilometers high and has a diameter of 160 km at its base. Its caldera has a diameter of 30 km and is 3 km deep, it can put inside a whole Mount Etna. Compared with terrestrial volcanoes the caldera is unusually deep, the elevation of the lowest level of the caldera being the same as the base of the volcano; however, the original lower slopes of Albor Tholus may have been covered by lava flows from its larger neighbor, Elysium Mons. Evaluations by the Mars probe Mars Express found that the volcanoes of the Elysium Region were active over long periods of time.


Topographical Map for Albor Tholus

Albor Tholus with THEMIS  the location is 17.6 degrees north latitude and 150.3 degrees east longitude.

To the northeast of Albor Tholus is the Iberus Vallis/ Elysium Fossae.


Wide view of Iberus Vallis, as seen by HiRISE.

Iberus Vallis is a valley in the Elysium Region of Mars, located at 21.5° N and 151.8 E. It is 80.2 km long and was named after a classical name for the Ebro River in NE Spain Much of the area in this region is also called the Elysium Fossae. In wide view of Iberus Vallis, as seen by HiRISE, imagine taking a walk in these canyons and looking up at the layers.


Close-up details of Iberus Vallis

We now travel back westward at the base of the larger Volcano through the Elysium Fossae to the Zephyrus Fossae. Fissures and channels seem to surround the Elysium Mons  Volcano and the Zephyrus Fossae surrounds it to the west.


Zephyrus Fossae

The trough wall has cut through and exposed layered bedrock, visible near the top of the wall. Talus covers the lower portions of the wall; this debris includes many automobile- and house-sized boulders---most of which are seen as dark dots at the base of the slope. Dust has coated and mantled much of this terrain, including some of the boulders. The dark streak near the center of the picture was formed by land-sliding (or avalanching) of some of the dust. Sunlight illuminates the scene from the lower left.



The Elysium Mons Volcano

The  Elysium Mons is located in the Elysium Region,  in the eastern hemisphere of Mars .  This volcano is much smaller than the volcanoes of Tharsis .  As with the Tharsis Montes, the Elysium Mons is located over a large surface bulge the result of massive flows of magma that escaped from inside the planet in the past.



Elysium Mons Topographical Map (note Albor Tholus in right corner)

Elysium Mons  a volcano on Mars is located at  25.02°N 147.21°E, It stands about 13.9 km (46,000 ft) above the surrounding lava plains, and about 16 km (52,000 ft) above the Martian datum. Its diameter is about 240 km (150 mi), with a summit caldera about 14 km (8.7 mi) across.  Elysium Mons was discovered in 1972 in images returned by the Mariner 9 orbiter.

To the northeast of the Elysium Mons is the Stygis Fossae. Like the Zephyrus Fossae it curves around the northeast side of the Volcano.


Stygis Fossae from Themis

From Here we head south and come to Ituxi Vallis, which is a valley in the Elysium Region of Mars.


Ituxi Vallis

Ituxi  Vallis is located at 25.4° N and 153°E. It is 62 km long and 19.2 km wide. It was named after the Ituxi River in Brazil.  Ituxi Vallis is a lava channel that lies east of Elysium Mons.

Just south of the Ituxi Vallis is the Patapsco Vallis.


Patapsco Vallis

Patapsco Vallis, as seen by HiRISE. Location is 23.9 North and 153.9 East.  Patapsco Vallis is a valley in the Elysium  Region of Mars.  It is 153 km long and was named after a modern river in Maryland, USA.

After that out in the middle of the plains  east of Albor Tholus we come to Thila Crater.


Thila Crater: is an impact crater in the Elysium quadrangle of Mars, located at 18.09° N and 155.5°E. It is 5.3 km in diameter and was named after Thila, Yemen.

The next major area  of importance that we come to after that is the Cerberus Fossae, which are combination or troughs, pits, and hills.  Pits are produced when material collapses into the void that results from stretching. Pit craters do not have rims or ejecta around them, like impact craters do. Studies have found that on Mars a fault may be as deep as 5 km, that is the break in the rock goes down to 5 km. Moreover, the crack or fault sometimes widens or dilates. This widening causes a void to form with a relatively high volume. When material slides into the void, a pit crater or a pit crater chain forms. On Mars, individual pit craters can join to form chains or even to form troughs that are sometimes scalloped. Other ideas have been suggested for the formation of fossae and pit craters. There is evidence that they are associated with dikes of magma. Magma might move along, under the surface, breaking the rock, and more importantly melting ice. The resulting action would cause a crack to form at the surface. Pit craters are not common on Earth. Sinkholes, where the ground falls into a hole (sometimes in the middle of a town) resemble pit craters on Mars. However, on the Earth these holes are caused by subsurface limestone being dissolved, thereby causing a void. The images of the Cerberus Fossae, the Elysium Fossae and other troughs, as seen by HiRISE are examples of fossae.  Knowledge of the locations and formation mechanisms of pit craters and fossae is important for the future colonization of Mars because they may be reservoirs of  water.


The Cerberus Fossae

Here are a series of semi-parallel fissures on Mars formed by faults which pulled the crust apart in the Cerberus region (9°N, 197°W). Ripples seen at the bottom of the fault are sand blown by the wind . The underlying cause for the faulting was magma pressure related to the formation of the Elysium Volcanic field, located to the northwest. The faults pass through pre-existing features such as hills, indicating that it is a younger feature. The formation of the fossae is suspected to have released pressurized underground water, previously confined by the cryosphere, leading to the creation of the Athabasca Valles.

Just southwest of the Cerberus Fossae is the the Athabasca Valles area an overflow region for water and probably lava too.  It is located at about 9°N 155°E. The Athabasca Valles is an outflow channel on Mars, cut into its surface by catastrophic flooding. It is one of the youngest known of these structures, probably forming only in the geologically recent past of Mars. The flood produced distinctive "teardrop" landforms similar to those found in the Channeled Scablands on Earth. It is thought that these landforms were produced though depositional processes wherein the floodwaters dropped sediment behind resistant bedrock outcroppings and craters.

Athabasca Valles Source, Islands, and Overflow Channels

The source of water for the flood is thought to be Cerberus Fossae, at 10 N and 157 E. Groundwater may have been trapped under a cryosphere which was broken when the fossae was created.  The very high spatial resolution images from the HiRISE camera on board the Mar Reconnaissance Orbiter have revealed that all the flood features are draped by lava flows.

Going southeast of Athabasca Valles through the Cerberus Tholi a region of hills and knobs we come to Tombaugh Crater.


Central Region of Tombaugh Crater

Tombaugh Crater is located at 3.6°N 162°E.  It is 60.3 km in diameter and is named after Clyde Tombaugh an American astronomer (1906–1997).

Going northeast from there we come to Zunil Crater.  Impact craters generally have a rim with ejecta around them, in contrast volcanic craters usually do not have a rim or ejecta deposits. As craters get larger (greater than 10 km in diameter) they usually have a central peak. The peak is caused by a rebound of the crater floor following the impact. Sometimes craters will display layers. Since the collision that produces a crater is like a powerful explosion, rocks from deep underground are tossed unto the surface. Hence, craters can show us what lies deep under the surface.


Zunil Crater

Research published in the journal Icarus has found pits in Zunil Crater that are caused by hot ejecta falling on ground containing ice. The pits are formed by heat forming steam that rushes out from groups of pits simultaneously, thereby blowing away from the pit ejecta.  Zunil Crater is 10.4 km in diameter and is named after a place name in Guatemala.

From there heading north we enter the Tartarus Montes.  This area is a long chain of mountains going northeast and then north into the Phlegra Dorsa.  The Tartarus Montes are a mountain range on the planet Mars, stretching over 1070 km and located around the coordinates 15.46º N, 167.54º E,  between Orcus Patera and the Elysium volcanic region.   The Albedo was first identified from the contrast of bright and dark signals photographed by Eugène Antoniadi.


Topographical Map of the Tartarus Montes

The mountain range was named in 1885. It has been named after Greek god of the underworld, Tartarus, by the standard planetary nomenclature for Martian landforms. According to Greek myth, Tartarus is the lowest part of Hades. Zeus imprisoned the Titans in Tartarus. The second part of the name "Montes" means mountains.


Part of the Tartarus Montes

Photographs taken by the Mars Global Surveyor indicate that there are cones and volcanic rings near the Tartarus Montes. Narrow grabens and fractures are present around the regions of this mountain range. Both the hilly areas and the intervening plains are cut with similar marks. This implies that there is a widespread tensional fracture system associated with Cerberus Fossae. At one point, the Grojta’ Vallis, an outflow channel, crosses the bedrock ridge of the Tartarus Montes.

Separating the southern part of the Tartarus Montes from the northern part there is a gap in which the Grojta Vallis crosses the  ridge at about 15.53°N 165.4°E.  The Grojta Vallis is 370 km long and is named after a river in Iceland.

Cratered Cones in Grjota Valles

North of the Grjota Valles and the Tartarus Montes lies the Phlegra Dorsa.   To the northwest near the northern border is Lockyer Crater.


Central Hills of Lockyer Crater

Lockyer Crater: is a crater in the Elysium Region of Mars, located at 28° North and 161°E.. It is 71 km in diameter and was named after Joseph N. Lockyer, a British astronomer (1836-1920).  Lockyer is fairly easy to spot on Mars maps because it sits in the relatively young northern hemisphere, where there are few craters. It is close to Elysium Mons  but to its  northeast.


Layers exposed in Lockyer Crater

The northeast corner of the Elysium Region is occupied by the Phlegra Dorsa.


This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows some dark slope streaks in the Phlegra Dorsa region of Mars. Of particular interest is the split streak near the center of the image, which diverted around a rounded hill as the material was sliding down the slope. Slope streaks occur in regions of Mars that are mantled by fine, bright dust. They do not occur on slopes that have no dust coating. They are therefore suspected to form by dry avalanching of the dust, despite their somewhat fluid appearance.

The Phlegra Dorsa Area

South of the Phlegra Dorsa is the Orcus Patera.  The Orcus Patera is a unique region on the surface of the planet Mars. It is a depression about 380 km long, 140 km wide, and about 0.5 km (500 meters) deep but with a relatively smooth floor. It has a rim up to 1.8 km high. Orcus Patera is west of Mons Olympus and east of Elysium Mons. It is about half-way between those two volcanoes, and east and north of Gale crater.  It has experienced Aeolian processes, and has some small craters and graben structures. However, it is not known how the Patera originally formed. Theories include volcanic, tectonic, or cratering events.  The coordinates are 177°E and between 11-17.5°N. It is a huge elongated feature right on the border of two regions.


Topographical Map of Orcus Patera


Orcas Patera

The term ‘patera’ is used for deep, complex or irregularly shaped volcanic craters such as the Hadriaca Patera and Tyrrhena Patera at the north-eastern margin of the Hellas impact basin. However, despite its name and the fact that it is positioned near volcanoes, the actual origin of Orcus Patera remains unclear.   Aside from volcanism, there are a number of other possible origins. Orcus Patera may be a large and originally round impact crater, subsequently deformed by compressional forces. Alternatively, it could have formed after the erosion of aligned impact craters. However, the most likely explanation is that it was made in an oblique impact, when a small body struck the surface at a very shallow angle, perhaps less than five degrees from the horizontal.


Orcas Patera Perspective view

The existence of tectonic forces at Orcus Patera is evident from the presence of the numerous ‘graben’, rift-valley-like structures that cut across its rim. Up to 2.5 km wide, these graben are oriented roughly east–west and are only visible on the rim and the nearby surroundings.  Within the Orcus Patera depression itself, the large graben are not visible, probably having been covered by later deposits. But smaller graben are present, indicating that several tectonic events have occurred in this region and also suggesting that multiple episodes of deposition have taken place.  The occurrence of ‘wrinkle ridges’ within the depression proves that not only extensional forces, as would be needed to create graben, but also compressive forces shaped this region. The dark shapes near the center of the depression were probably formed by wind-driven processes, where dark material excavated by small impact events in the depression has been redistributed.

Just south of the Orcus Patera is the  Rahway Valles.


Rahway Valles

Rahway Valles is a valley in the Elysium quadrangle of Mars, located at 9.4° North and 175 °East. It is 500 km long and was named after a river in New Jersey, USA. Below that is the Marte Vallis an area we have explored earlier in the next region.   With that we have covered the northern half of the planet from the North Pole all the way to the Equator.

Thursday, November 7, 2013

Small Pale Red Planet Issue 2 Phase 8


The Amenthes Region


This Region contains the eastern part of the Isidis basin, a location where magnesium carbonate was found by MRO. This mineral indicates that water was present and that it was not acidic. Life may have formed in this area.  There are Dark slope streaks, troughs (fossae), and river valleys (Vallis) in this Region.  The Region is named for Amenthes the underworld of Ancient Egypt.


Topographical Map of the Amenthes Region

Some craters in the Amenthes region  show ejecta around them that have lobes. It is believed that the lobed shape is caused by an impact into water or ice saturated ground. Calculations suggest that ice is stable beneath the Martian surface. At the equator the stable layer of ice might lie under as much as 1 kilometer of material, but at higher latitudes the ice may be just a few centimeters below the surface. This was proven when the landing rockets on the Phoenix lander blew away surface dust to reveal an ice surface.


Image of the Amenthes Region

Starting in the northeast corner of the Region we continue exploring in the Utopia Planitia region.  A hard surface crust is formed by solutions of minerals moving up through soil and evaporating at the surface. Some areas of the surface exhibit what is called "scalloped topography,"

Utopia Planitia Scooped and Scalloped Terrain

Here the surface seems to have been carved out by an ice cream scoop. This surface is thought to have formed by the degradation of an ice-rich permafrost.


This photo shows a thin coating of water ice on the rocks and soil in Utopia Planitia

The time the frost appeared corresponds almost exactly with the buildup of frost after one Martian year (23 Earth months). Then it remained on the surface for about 100 days. Scientists believe dust particles in the atmosphere pick up bits of solid water. That combination is not heavy enough to settle to the ground. But carbon dioxide, which makes up 95 percent of the Martian atmosphere, freezes and adheres to the particles and they become heavy enough to sink. Warmed by the Sun, the surface evaporates the carbon dioxide and returns it to the atmosphere, leaving behind the water and dust. The ice seen in this picture, is extremely thin, perhaps no more than one-thousandth of a centimeter thick. The view is looking towards the south southeast.

From here as we go southward from 25°N - 5°N and from 90-100°East we enter the eastern part of the Isidis Planitia.


The northern part of Isidis Planitia in the north of the Amenthes Region at 19°N 97°E.


Crater with Central Peak in the central area of the Isidis Planitia in the Amenthes Region at 14°N 91°E.

A part of the Libya Montes enters the region from the southwest with the Crater Du Martheray in its north center.


Du Martheray Crater lies at the Southern boundary of the Isidis Planitia in the Amenthes Region

Du Martheray Crater is located at 6°N 93°E and is 102 km in diameter.  It was named after Maurice du Martheray (1892 – April 12, 1955)  a Swiss astronomer and poet.

After passing through this area we enter the northern part of Tyrrhena Terra which takes us to the Equator. Tyrrhena Terra is a large area on Mars, centered mostly south of the Martian equator and immediately northeast of the Hellas basin. Its coordinates are  14.8°S 90°E, and it covers an area of 2300 km at its broadest extent.

Valleys in Northern Tyrrhena Terra

Going north from this region we come to the  Amenthes Fossae. It is a trough in the Amenthes Region of Mars located at 9.07 N and 102.68 E. It is 850 km across and was named after the classic albedo feature name of the Region.


Amenthes Fossae Trough - Details of wall of trough, as seen by HI rise, under HI Wish program. Location is 6.7 N and 99.4 E.

Then going east of there we come to the Amenthes Planum which separates the Tyrrhena Terra to the west  from the Terra Cimmeria on the east side. So Amenthes Planum is a plateau that runs between them separating them.  The Amenthes Planum is 960 km in diameter.


Channels along the Eastern Margin of the Amenthes Planum

The Amenthes Fossae has two locations one that is a fissure that goes to the west of Amenthes Planum from about 5-13°N and there is another part of it that appears to the east of Amenthes Planum running  from about 7-14°N.


Central Peak of Crater in Amenthes Fossae Region 9°N 106°E

Going north from there we enter the plains once again, the   Nepenthes Planum.   This area is composed of many small craters.


Isolated Massif in Nepenthes Planum

One of the first craters of note that we come to in this area  is Onon Crater.


Onan Crater

Scale bar is 500 meters long. Location is 16.1 degrees north latitude and 102.5 degrees east longitude. Image was taken by the Mars Reconnaissance Orbiter's HiRISE.  The crater is 3.5 km in diameter and many of the others in the area are of a similar size.  Onan is a Mongolian place name. It is an impact crater but it is almost in a perfect circular shape which means it was probably made in recent history.

The next crater we come to is further north.  Slightly to the northeast at 19°N 105°E is Viana Crater.


Viana Crater (red dot in center)

As I said there are a large number of small craters in this area, Viana is one of the larger ones here.  Viana Crater is 30 km in diameter and was named  after a Brazilian place name.

We now continue northward and enter the Utopia Planitia again which takes us all the way to the northern border of the Amenthes Region.   Heading back south at about 110°E we enter the area of small craters again and come to Marbach Crater at 17°N. We enter the  Amenthes Nepenthes area again.


Marbach Crater (red dot in center)

Marbach Crater is located at  17.8°N 249.0°W.  It is 25.8 km in diameter and is name after a Switzerland place name.

Continuing south as we pass over 10°N we enter Terra Cimmeria.  Terra Cimmeria is a large Martian region, centered at   34.7°S 145°E and covering 5,400 km (3,400 mi) at its broadest extent. It covers latitudes 15 N to 75 S and longitudes 170 to 260 W. Terra Cimmeria is one part of the heavily cratered, southern highland region of the planet. The Spirit rover landed near the area.  A high altitude visual phenomena, probably a condensation cloud, was seen above this region in late March 2012.

Gullies in the Crater Walls in Terra Cimmeria

Terra Cimmeria is the location of gullies that may be due to recent flowing water.  Gullies occur on steep slopes, especially on the walls of craters. Craters are believed to be relatively young because they have few, if any gullies. Moreover, gullies lie on top of sand dunes which themselves are considered to be quite young. Usually, each gully has an alcove, channel, and apron. Some studies have found that gullies occur on slopes that face all directions, others have found that the greater number of gullies are found on pole-ward facing slopes, especially from 30-44 degrees S.  Although many ideas have been put forward to explain them, the most popular involve liquid water coming from an aquifer, from melting at the base of old glaciers, or from the melting of ice in the ground when the climate was warmer.  Because of the good possibility that liquid water was involved with their formation and that they could be very young, scientists are excited. Maybe the gullies are where we should go to find life. There is evidence for all three theories. Most of the gully alcove heads occur at the same level, just as one would expect of an aquifer. Various measurements and calculations show that liquid water could exist in aquifers at the usual depths where gullies begin.  One variation of this model is that rising hot magma could have melted ice in the ground and caused water to flow in aquifers. Aquifers are layers of rock that allow water to flow. They may consist of porous sandstone. The aquifer layer would be perched on top of another layer that prevents water from going down (in geological terms it would be called impermeable). Because water in an aquifer is prevented from going down, the only direction the trapped water can flow is horizontally. Eventually, water could flow out onto the surface when the aquifer reaches a break—like a crater wall. The resulting flow of water could erode the wall to create gullies.  As for the next theory, much of the surface of Mars is covered by a thick smooth mantle that is thought to be a mixture of ice and dust. This ice-rich mantle, a few yards thick, smoothens the land, but in places it has a bumpy texture, resembling the surface of a basketball. The mantle may be like a glacier and under certain conditions the ice that is mixed in the mantle could melt and flow down the slopes and make gullies.  The third theory might be possible since climate changes may be enough to simply allow ice in the ground to melt and thus form the gullies. During a warmer climate, the first few meters of ground could thaw and produce a "debris flow" similar to those on the dry and cold Greenland east coast. Since the gullies occur on steep slopes only a small decrease of the shear strength of the soil particles is needed to begin the flow. Small amounts of liquid water from melted ground ice could be enough. Calculations show that a third of a mm of runoff can be produced each day for 50 days of each Martian year, even under current conditions.

In Terra Cimmeria on the Equator we come to the Escalante Crater.  So that puts it at 0°on the map.  It is also located partly in the Region to to the south.  But more of it is on the north side than the south side.  It  located between 115-116°E degrees on the Equator.


Escalante Crater Walls

Escalante Crater is an impact crater in the Amenthes Region of Mars. It is located at 0.2° N and 244.7° W. It is 79.3 km (49.3 mi) in diameter, and was named after Mexican astronomer (c. 1930) F. Escalante.

To the northeast of that crater is Ehden Crater.


Central Peak of Ehden Crater

Ehden Crater is located at 8.2°N 241.1°W.  It is 57.7 km in diameter and is named after a Lebanon place name.

Going to the northeast from there we enter the Nepenthes Planum again and then enter another large area called the  Amenthes Cavi.


Cone-Shaped Feature with Summit Pit in Amenthes Cavi.

The Amenthes Cavi area covers an area from 13-17°N and 110-125°E.  Going northeast from there we come to the Hephaestus Fossae.


Hephaestus Fossae -Two Views, as seen by HiRISE. Location is 21.7 degrees north latitude and 122.3 degrees east longitude.

The Hephaestus Fossae are a system of troughs and channels that start in the Cebrenia Region of Mars, then flow south into the Amenthes Region, with a location centered at 21.1 N and 237.5 W. It is 604 km long and was named after a classical albedo feature name. The fossae have been tentatively identified as outflow channels, but their origin and evolution remain ambiguous. It has been proposed that water may have been released into the troughs as a catastrophic flood due to subsurface ice melting following a large bolide impact.

To the east of the Hephaestus Fossae we come to the Hebrus Valles.


Hebrus Valles

The Hebrus Valles: is an ancient system of troughs and valleys in the Amenthes Region of Mars, located at 20.2° north latitude and 233.4° west longitude. It is 317 km long and was named after a river in the Balkans which runs through present day Bulgaria, Greece and Turkey. Some authors have identified the troughs and valleys of Hebrus Valles as outflow channels, but their origin and history remain ambiguous.  Hebrus Valles has tributaries, terraces, and teardrop shaped islands. These features are all characteristic of erosion by fluid flow, but may or may not support the identification of this feature as carved by a single catastrophic outburst flood of water (as the term outflow channel would imply). The tear drop shape of the islands indicate what direction the water used to flow. The terraces may be caused by different layers of rocks or from the water being at different levels.  These features are common for the rivers of the Earth.

Continuing North we go through the Hephaestus Rupes which is also a part of the Utopia Planitia. 


Mesa Near Hephaestus Rupes

This particular Mesa is located at 20°N and 123°E.  Rupes is Latin for cliffs or escarpments so this is the type of terrain we traveling through in this part of the Amenthes Region.

Heading to the northeastern corner of the Region we come the Granicus and Tinjar Vallis in the same area together.  We come to Tinjar Vallis first which is located to the northern border of the Amenthes Region.


Tinjar Vallis

Tinjar Vallis is an ancient outflow channel in the Amenthes Region of Mars, it is located at 38° north latitude and 125.8° east longitude. It is 425 km long and was named after a modern river in Sarawak, Malaysia.  Next as we head east we come to the Granicus Vallis.


The Granicus Vallis

The Granicus Vallis is a valley in the Amenthes Region of Mars, located at 30° north latitude and 129° east longitude. It is 750 km long and is named after the ancient name for river in Turkey. It has been identified as an outflow channel.

Going south along the eastern border of the Amenthes Region we come to the Hyblaeus Fossae.


Hyblaeus Fossae

These fissures are located at 21°N and 137°E.  The diameter of Hyblaeus Fossae is 400 km. and it extends into the next Region to the east it is named after an albedo feature.

The next area we enter is the Hyblaeus Dorsa.  Located from 15-10° N (going southward) and 125°E.  Dorsa in Latin means a hilly or knobby type region.


Sample of Northern Hyblaeus Dorsa

Following this we enter the Elysium Planitia which occupies the southeast corner of the Amenthes Region but also shares it with the Nepenthes Mensae.


Nepenthes Mensae

Between the highlands of Terra Cimmeria and the low plains of Elysium Planitia and Nepenthes Planum lies the rugged region called Nepenthes Mensae. Hills in this region vary in height and the surrounding surface can vary greatly in texture - from dune forms to low ridges to smooth terrain.

The Elysium Planitia, located in the Elysium and Aeolis, and Amenthes Regions,  is a broad plain that straddles the equator of Mars, centered at  3.0°N 154.7°E. It lies to the south of the volcanic province of Elysium, the second largest volcanic region on the planet, after Tharsis.

Crater in the Elysium Planitia

Martian Dust and Dust Storms:


Before and after a Planet-wide Dust Storm

Mars dust storms are much different than the dust devils that many people have seen in images sent back from the planet. On Mars a dust storm can develop in a matter of hours and envelope the entire planet within a few days. After developing, it can take weeks for a dust storm on Mars to completely expend itself. Scientists are still trying to determine why the storms become so large and last so long.  All Mars dust storms are powered by sunshine. Solar heating warms the Martian atmosphere and causes the air to move, lifting dust off the ground. The chance for storms is increased when there are great temperature variations like those seen at the equator during the Martian summer. Because the planet’s atmosphere is only about 1% as dense as Earth’s only the smallest dust grains hang in the air.

Two Dust Devils on Mars

The dust storms were of great concern when probes were first sent to Mars. Early probes happened to arrive in orbit during large events. The Viking missions of 1976 easily withstood two big dust storms without being damaged. They were not the first missions to survive Martian dust storms. In 1971, Mariner 9 arrived at Mars during the biggest dust storm ever recorded. Mission controllers simply waited a few weeks for the storm to subside, then carried on with the mission. The biggest issue that rovers face during a dust storm is the lack of sunlight. Without the light, the rovers have trouble generating enough power to keep their electronics warm enough to function.  Mars dust storms are of great interest to scientists. Even though several spacecraft have observed the storms first hand, scientists are no closer to a definitive answer. For now, the storms on Mars are going to continue to present challenges to planning a human mission to the planet.  According to a NASA report that evaluates the risks of sending a manned mission to Mars. Martian dust poses as one of the biggest potential problems.  Compared to here, dust on Mars is thought to be larger and rougher, like the dust that covers the Moon. When Apollo astronauts landed there, they were covered in it in just a few minutes. Within hours, rough lunar dust had scratched up lenses and degraded seals.  While the lunar stays were short, if astronauts make the six-month journey to Mars, they’ll likely be expected to stay a while. That would give potentially hazardous dust plenty of time to accumulate in equipment, cause airlock malfunctions, or even infiltrate astronauts’ lungs.  “Martian dust is a number one risk,” says Jim Garvin, NASA chief scientist at the Goddard Space Flight Center. “We need to understand the dust in designing power systems, space suits and filtration systems. We need to mitigate it, keep it out, figure out how to live with it.”  Dust on Mars doesn’t just sit on the ground – it gets furiously swept about in dust devils and massive dust storms. Thus recently sky watchers could easily spot an 800-mile-wide dust storm as it spun across Mars at 35 mph.

Living with Dust Storms on Mars

Every once and a while, Mars experiences the “perfect dust storm,” where powerful winds kick dust up into the atmosphere where it is spread around until it eventually clouds the entire planet.  One of these rare storms would obviously make it difficult for a spacecraft to land or take off from the planet’s surface, but even smaller storms could be  a substantial mission risk, making atmospheric wind forces the number two mission risk, according to the report.  “We could observe Martian wind speeds at different altitudes, which is vital both for targeting accuracy when a mission lands, and for reaching the right orbit when the mission departs,” said David Beaty, Mars Program Science Manager and the report’s lead author.  Although signs of life haven’t been discovered on Mars, that might be a different story in 25 years. The possibility that microbial organisms, or their remains, could exist in Martian soil is ranked as the number three mission risk.  Having never been exposed to these forms of alien life, they could stand as a substantial health risk to astronauts. The biggest concern to scientists, though, is that these life forms might hitch a ride back to Earth, where they could replicate, prosper, and do unknown damage. Scientists say they need more robotic missions and soil sample returns to truly evaluate this risk. Even a couple pounds of Martian dirt would be of tremendous value, Beaty said.  The same problem was addressed with the Apollo Missions to the Moon when the astronauts were quarantined upon their return.  There should be an easy way to prevent cross-planet contamination through the use of shuttles and space stations should such danger arise.

Dust Chemical Composition Average:

Infrared spectra obtained from the Mariner 9 spacecraft during the 1971–1972 dust storm are used to derive information on the composition and particle size distribution of the dust and to study the time evolution of the storm. The dust is not composed of pure granite, basalt, basaltic glass, obsidian, quartz, andesite, or montmorillonite. The infrared spectra suggest that the dust is a mixture of materials, dominated by igneous silicates with >62;60% SiO2,  or weathering products such as clay minerals, but the dust could possibly have a significant component of lower SiO2 materials such as basalt. Substantial quantities of carbonates, nitrates, or carbon sub-oxide are excluded from the mixture. All infrared, visible, and ultraviolet data on the Martian surface composition seem consistent with a mixture of basalt and clay minerals or high SiO2 igneous rocks, with a surface patina of oxides of iron.