Topographical Map of the Aeolis Region
The Reason this Phase has been split into two Phases (chapters) is there is a large amount of information discovered by the Curiosity and the Spirit Rovers that need to be considered. Since we are finished with Curiosity this Phase will deal with the Spirit Rover which did it’s work while it was operational on the opposite (east) side of the Aeolis Region.
Going eastward in the Elysium Planitia in the north of the Aeolis Region we come to the Avernus Colles at 171°1°S.
Avernus Colles is a region of hills' separated by arcuate (delta-like) fractures. These features are the margin between the southern highlands and Elysium Planitia to the north. This VIS image shows a portion of Avernus Colles. The term "colles" means small hills, and the surface here is being fractured into many small hills and mesas.
To the southeast of the Avernus Colles are the Avernus Cavi at about 173°E 4°S.
Avernus Cavi Fractures
Cavi means exactly what it sounds like- the Avernus Cavi are pits or cavities in the terrain of Mars
Depression in Avernus Cavi Region
To the southwest of the Cavi is the ridges of the Avernus Dorsa between 170-171°E and as far south as 9°S.
Avernus was believed to be the entrance to the underworld, and is portrayed as such in the Aeneid of Virgil. So the name has a classical origin.
To the east of the Avernus Cavi is the Tartarus Scopulus which occupies the northeast corner of the Aeolis Region.
Tartars Scopulus is an area of lobate scarps. Tartarus is a classical term for the hell where people were judged in the classical poets.
Apollinaris Patera, a large volcano, which lies directly north of Gusev Crater. It is located at 174°E 9°S.
Apollinaris Patera (Apollinaris Mons)
In April 1999, the Mars Global Surveyor Mars Orbiter Camera (MOC) passed over the Apollinaris Patera volcano and captured a patch of bright clouds hanging over its summit in the early Martian afternoon. This ancient volcano is located near the equator and--based on observations from the 1970s Viking Orbiters--is thought to be as much as 5 kilometers (3 miles) high. The caldera--the semi-circular crater at the volcano summit--is about 80 kilometers (50 miles) across. Apollinaris Mons is an ancient shield volcano in the southern hemisphere of Mars. It is situated near the equator, south of Elysium Planitia and north of Gusev crater. Elysium Planitia separates it from the volcanic province of Elysium to its northwest. The volcano's caldera is named Apollinaris Patera; this name formerly applied to the whole edifice. Apollinaris Mons is about 5 kilometers high with a base about 296 kilometers in diameter. On the top of this volcano is a caldera about 80 km (50 miles) in diameter. The volcano is approximately 3 to 3.5 billion years old. It was named in 1973 after a mountain spring near Rome in Italy. A study using a global climate model found that the Medusae Fossae Formation could have been formed from ash from Apollinaris Mons, Arsia Mons, and possibly Pavonis Mons.
To the east of the Volcano is the Matrona Vallis located at 176°E 8°S.
Matrona Vallis is 51 kilometers long and is named after the classical name for Marne River in France.
To the east of the Matrona Valles all the way to the eastern border of the Aeolis Region is the Lucus Planum. Roughly 177-180°E and 5-10°S.
A Fading Impact Crater in Lucus Planum
This cluster of craters formed quite recently from a weak impacter that broke apart in Mars' thin atmosphere before smashing into the surface. It was discovered by the MRO Context Camera (CTX) Team, who found a dark spot in a CTX image taken in August 2008 that was not present in earlier Mars Odyssey Mission THEMIS images from July 2005. HiRISE examined the feature in October 2008 and verified that the dark spot was impact ejecta excavated from beneath the bright surface. On June 25 2012, HiRISE took another look at the young crater to see how it had fared after two Martian years. This image was timed to closely match the illumination and viewing conditions of the earlier HiRISE image. A comparison of the two images shows that the dark halo surrounding the crater cluster has nearly vanished. The delicate rays extending beyond the halo are also significantly faded. Only the individual craters remain distinctly dark in the new image. This observation is important for two reasons. First, it raises questions about the Martian winds and sediments that produce such changes. Did the dark ejecta blow away, or was it buried by a layer of bright dust? Second, it tells us that the window for detection of these young craters can be very short. In this case, the dark spot that drew the attention of the Context Camera Team was the 200-meter diameter halo of ejecta that encircled the crater cluster. After two Martian years, the halo is gone and the impact cluster would not be easily detected.
The Lucas Planum area is located east of the Apollinaris Mons all the way to the eastern border of the Aeolis Region. It is a plateau that stretches from 176.5°E to 180°E and from 5 to 10°S.\
Wind Erosion in Lucus Planum
The action of the wind continues to shape the surface of Mars. This region has been eroded by the wind into parallel hills.
To the west of Apollinaris Mons there is Reuyl Crater centered at 167°E 10°S.
This Martian feature and was named after Dirk Reuyl, a Dutch-American physicist and astronomer (1906–1972) who made astronomical measurements of the diameter of Mars in the 1940s.
To the southeast of Reuyl Crater is Zephyria Mensae located at 177°E 11°S.
A Mensae is a Mesa in planetary geology. Mensae are usually grouped with Fretted terrain, which is a type of surface feature common to certain areas of Mars and was discovered in Mariner 9 images. It lies between two different types of terrain. The surface of Mars can be divided into two parts: low, young, un-cratered plains that cover most of the northern hemisphere, and high-standing, old, heavily cratered areas that cover the southern and a small part of the northern hemisphere. In fretted terrain, the land seems to transition from narrow straight valleys to isolated mesas. Most of the mesas are surrounded by forms that have been given a variety of names: circum-mesa aprons, debris aprons, rock glaciers, and lobate debris aprons. At first, they appeared to resemble rock glaciers on Earth. But scientists could not be sure. Even after the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) took a variety of pictures of fretted terrain, experts could not tell for sure if material was moving or flowing as it would in an ice-rich deposit (glacier). Eventually, proof of their true nature was discovered when radar studies with the Mars Reconnaissance Orbiter showed that they contained pure water ice covered with a thin layer of rocks that insulated the ice.
Just to the south of Zephyria Mensae the area opens up into a huge crater called de Vaucouleuers Crater centered at 171°E 13°S.
de Vaucouleurs Crater
de Vaucouleurs Crater is 293 Kilometers in diameter and was named after Gérard Henri de Vaucouleurs (25 April 1918 – 7 October 1995) who was a French astronomer. He specialized in the study of galaxies and was co-author of the Third Reference Catalogue of Bright Galaxies.
Mars Exploration Rover Landing Site at Gusev Crater HiRISE DTM
“Spirit”, MER-A (Mars Exploration Rover – A), was a robotic rover on Mars, active from 2004 to 2010. It was one of two rovers of NASA's ongoing Mars Exploration Rover Mission. It landed successfully on Mars at 04:35 Ground UTC on January 4, 2004, three weeks before its twin, Opportunity (MER-B), landed on the other side of the planet. Its name was chosen through a NASA-sponsored student essay competition.
Mars Exploration Rover "Spirit" took this mosaic on 16th sol. It shows the now useless landing sheath at the landing site.
Schematic of the rover type that is Spirit and Opportunity
Adirondack is the nickname for Mars Exploration Rover Spirit's first target rock. Scientists chose Adirondack to be Spirit's first target rock after considering another, called Sashimi, that would have been a shorter, straight-ahead drive. Spirit traversed the sandy Martian terrain at Gusev Crater to arrive in front of this football-sized rock on January 18, 2004, just three days after it successfully rolled off the lander. Scientists named the angular rock after the Adirondack mountain range in New York. The rock was selected as Spirit's first target because its dust-free, flat surface is ideally suited for grinding. Clean surfaces also are better for examining a rock's top coating. Spirit has also returned microscopic images and Mössbauer spectrometer readings of Adirondack taken the day before the rover developed computer and communication problems on January 22, 2004. Both are unprecedented investigations of any rock on another planet. The microscopic images indicate Adirondack is a hard, crystalline rock. The peaks large and small in Adirondack's electromagnetic spectrum reveal that the minerals in the rock include olivine, pyroxene and magnetite - a common composition in volcanic basalt rocks on Earth.
The round, shallow depression in this image resulted from history's first grinding of a rock on Mars.
Adirondack has been very slightly altered, probably by thin films of water because they are softer and contain veins of light colored material that may be bromine compounds, as well as coatings or rinds. It is thought that small amounts of water may have gotten into cracks inducing mineralization processes.
The Spirit Rover discovered that the rocks on the plains of Gusev are a type of basalt. They contain the minerals olivine, pyroxene, plagioclase, and magnetite, and they look like volcanic basalt as they are fine-grained with irregular holes (geologists would say they have vesicles and vugs). Much of the soil on the plains came from the breakdown of the local rocks. Fairly high levels of nickel were found in some soils; probably from meteorites. Analysis shows that the rocks have been slightly altered by tiny amounts of water. Outside coatings and cracks inside the rocks suggest water deposited minerals, maybe bromine compounds. All the rocks contain a fine coating of dust and one or more harder kinds of material. One type can be brushed off, while another needed to be ground off by the Rock Abrasion Tool (RAT).
Apollo Hills Panorama
There are a variety of rocks in the Columbia Hills (Mars), some of which have been altered by water, but not by very much water. The dust in Gusev Crater is the same as dust all around the planet. All the dust was found to be magnetic. Moreover, Spirit found the magnetism was caused by the mineral magnetite, especially magnetite that contained the element titanium. One magnet was able to completely divert all dust hence all Martian dust is thought to be magnetic. The spectra of the dust was similar to spectra of bright, low thermal inertia regions like Tharsis and Arabia that have been detected by orbiting satellites.
Spirit Rover First Three Years
Humphrey Rock: "If we found this rock on Earth, we would say it is a volcanic rock that had a little fluid moving through it," Arvidson said. If this interpretation is correct, the fluid -- water with minerals dissolved in it -- may have been carried in the original magma that formed the rock or may have interacted with the rock later, he said. The clues appear in an interior exposure of "Humphrey" where Spirit's rock abrasion tool scraped away the rock's surface to a depth of 2 millimeters (.08 inch). To gain more confidence that the bright material seen in cracks and pores is not dust that has intruded from the surface over the millennia, scientists intend to have Spirit grind more deeply into another dark rock, not yet selected. The bright material is not debris from the grinding process, said Stephen Gorevan of Honeybee Robotics, New York, lead scientist for the abrasion tool.
Bonneville crater On sol 65 March 11, 2004, the Spirit rover reached Bonneville crater after a 400-yard (370 m) journey. This crater is about 200 meters (220 yd) across with a floor about 10 meters (11 yd) below the surface. JPL decided that it would be a bad idea to send the rover down into the crater, as they saw no targets of interest inside. Spirit drove along the southern rim and continued to the southwest towards the Columbia Hills.
Dust whirlwinds (dust devils):On March 9, 2005 (probably during the Martian night), the rover's solar panel efficiency jumped from around 60% of what it had originally been to 93%, followed on March 10, by the sighting of dust devils. NASA scientists speculate a dust devil must have swept the solar panels clean, possibly significantly extending the duration of the mission. This also marks the first time dust devils had been spotted by either Spirit or Opportunity, easily one of the top highlights of the mission to date. Dust devils had previously been photographed by only the Pathfinder probe. Mission members monitoring the Spirit rover on Mars reported on sol 421 March 12, 2005, that a lucky encounter with a dust devil had cleaned the solar panels of that robot. Power levels dramatically increased and daily science work was anticipated to be expanded.
Husband Hill: As of August Spirit was only 100 meters from the top away. Here they had found out that Husband Hill has two summits, with one a little higher than the other. On September 29, the 618th sol Spirit reached the real summit of Husband Hill. The rover was the first spacecraft to climb atop a mountain on another planet. The whole driven distance summed up to 4971 meters. The summit itself was flat. Spirit took a 360 degree panorama in real color, which included the whole Gusev crater. At night the rover observed the mars moons Phobos and Deimos in order to determine their orbits better. On sol 656 Spirit surveyed the mars sky and the atmospheric opacity with its pan-cam to make a coordinated science campaign with the Hubble space telescope in the earth orbit.
Comanche Rock Outcrop: From the peak Spirit could spot a striking formation, which was dubbed Home Plate. This was an interesting target, but Spirit should be drive later to the McCool Hill to tilt its solar panels towards the sun in the coming winter. At the end of October the rover was driven downhill and to Home Plate. On the way down Spirit reached a rock formation named Comanche on sol 690. Scientists used data from all three spectrometers to find out that about one-fourth of the composition of Comanche is magnesium iron carbonate. That concentration is 10 times higher than for any previously identified carbonate in a Martian rock. Carbonates originate in wet, near-neutral conditions but dissolve in acid. The find at Comanche is the first unambiguous evidence from the Mars Exploration Mission rovers for a past Martian environment that may have been more favorable to life than the wet but acidic conditions indicated by the rovers' earlier finds. A scientist in the video says the rover was not intended to search for life-then I would like to know why it was sent there for in the first place ?
While at Low Haven Ridge: Spirit imaged two rocks of similar chemical nature to that of Opportunity's Heat Shield Rock, a meteorite on the surface of Mars. Named "Zhong Shan" for Sun Yat-sen and "Allan Hills" for the location in Antarctica where several Martian meteorites have been found, they stood out against the background rocks that were darker. Further spectrographic testing is being done to determine the exact composition of these rocks, which may turn out to also be meteorites.
Silica Valley: Rover exposes silica-rich dust. Spirit's dead wheel turned out to be a mixed blessing. As it was traveling in March 2007, pulling the dead wheel behind, the wheel scraped off the upper layer of the Martian soil, uncovering a patch of ground that scientists say shows evidence of a past environment that would have been perfect for microbial life. It is similar to areas on Earth where water or steam from hot springs came into contact with volcanic rocks. On Earth, these are locations that tend to teem with bacteria, said rover chief scientist Steve Squyres. "We're really excited about this," he told a meeting of the American Geophysical Union (AGU). The area is extremely rich in silica–the main ingredient of window glass. The researchers have now concluded that the bright material must have been produced in one of two ways. One: hot-spring deposits produced when water dissolved silica at one location and then carried it to another (i.e. a geyser). Two: acidic steam rising through cracks in rocks stripped them of their mineral components, leaving silica behind. "The important thing is that whether it is one hypothesis or the other, the implications for the former habitability of Mars are pretty much the same," Squyres explained to BBC News. Hot water provides an environment in which microbes can thrive and the precipitation of that silica entombs and preserves them. Squyres added, "You can go to hot springs and you can go to fumaroles and at either place on Earth it is teeming with life – microbial life.
The Martian Plains:: "This is the first color image of Mars taken by the panoramic camera on the Mars Exploration Rover Spirit. It was the highest resolution image ever taken on the surface of another planet."
Spirit's miniature thermal emission spectrometer observed the patch of Silica, and Steve Ruff of Arizona State University, Tempe, noticed that its spectrum showed a high silica content. The team has laid out plans for further study of the soil patch and surrounding deposits. Exploring a low range of hills inside a Connecticut-sized basin named Gusev Crater, Spirit had previously found other indicators of long-ago water at the site, such as patches of water-bearing, sulfur-rich soil; alteration of minerals; and evidence of explosive volcanism.
Cross-sectional drawing of a typical rock from the plains of Gusev crater. Most rocks contain a coating of dust and one or more harder coatings. Veins of water-deposited veins are visible, along with crystals of olivine. Veins may contain bromine salts.
Columbia Hills: Scientists found a variety of rock types in the Columbia Hills, and they placed them into six different categories. The six are: Clovis, Wishbone, Peace, Watchtower, Backstay, and Independence. They are named after a prominent rock in each group. Their chemical compositions, as measured by APXS, are significantly different from each other. Most importantly, all of the rocks in Columbia Hills show various degrees of alteration due to aqueous fluids. They are enriched in the elements phosphorus, sulfur, chlorine, and bromine—all of which can be carried around in water solutions. The Columbia Hills’ rocks contain basaltic glass, along with varying amounts of olivine and sulfates. The olivine abundance varies inversely with the amount of sulfates. This is exactly what is expected because water destroys olivine but helps to produce sulfates. The Clovis group is especially interesting because the Mössbauer spectrometer(MB) detected goethite in it. Goethite forms only in the presence of water, so its discovery is the first direct evidence of past water in the Columbia Hills's rocks. In addition, the MB spectra of rocks and outcrops displayed a strong decline in olivine presence, although the rocks probably once contained much olivine. Olivine is a marker for the lack of water because it easily decomposes in the presence of water. Sulfate was found, and it needs water to form. Wishstone contained a great deal of plagioclase, some olivine, and anhydrate (a sulfate). Peace rocks showed sulfur and strong ev
idence for bound water, so hydrated sulfates are suspected. Watchtower class rocks lack olivine consequently they may have been altered by water. The Independence class showed some signs of clay (perhaps montmorillonite a member of the smectite group). Clays require fairly long term exposure to water to form. One type of soil, called Paso Robles, from the Columbia Hills, may be an evaporate deposit because it contains large amounts of sulfur, phosphorus, calcium, and iron. Also, MB found that much of the iron in Paso Robles soil was of the oxidized, Fe+++ form, which would happen if water had been present.
In 2009 the Spirit got stuck in soft soil (also known as the “sand trap“) and was unable to gain traction to get the solar panels into a position to recharge the batteries. It was decided in 2010 to give Spirit a stationary mission. But the battery power had ran down to the point that by March 2010 Spirit ceased to be operational and has been that way ever since and no further communication was possible. Thus the end of the Mission of the Mars Rover Spirit.
To the southwest of Gusev Crater is Kayne Crater at 174°E 15.5°S.
Central Uplift of Kayne Crater
Kayne Crater is 34.9 kilometers in diameter and is named after a Botswana place name.
To the southwest of Kayne Crater is the Durius Valles 171.5°E 16°S.
Durius Valles is 223 kilometers in length and is named for Classical name for the Douro River in Portugal.
Directly east of this feature is the Apollinaris Tholus at 176°E 17.5°S.
Location of Apollinaris Tholus
Apollinaris Tholus is a mountain to the south of Gusev Crater and to the west of the deep and long Ma’adim Vallis .
To the southwest is another mountain Zephyria Tholus located at 175.5°E 19.5°S.
This image covers some high-standing topography just outside the rim of an approximately 30 kilometer diameter impact crater. What formed this hill? Could it be a volcano? That was hypothesized to be the case in a paper published in 2001, and this suggestion was entered to test that idea, perhaps from seeing internal layering exposed by the crater. So what does the HiRISE image show us? Mostly it shows a dust mantle, hiding the bedrock it was intended to study. This photo was taken near the small dome-shaped mountain, Zephyria Tholus, which is located in Terra Cimmeria. The closest major feature to this location is Ma'adim Vallis, which is to the east.
Next we come to Ma’adim Valles which outflows into Gusev Crater from the south the source appears to be in the southeast corner of the Aeolis Region.
Ma’adim Vallis Riverbed
Ma'adim Vallis is a large, ancient river valley, enters at the south rim of Gusev Crater, therefore Gusev Crater was believed to be an ancient lake bed. However, it seems that a volcanic flow covered up the lakebed sediments. This image shows a network of small valleys in the Terra Cimmeria region of the Martian southern highlands. This location is approximately 1,000 kilometers (600 miles) south of Gusev Crater, the landing site of the Mars Exploration Rover Spirit. The valleys in this image are carved into light-toned bedrock exhibiting a range of colors, which likely reflect a range of mineralogical compositions. The bedrock is pervasively fractured, and some of the fractures appear to be filled with material of a different color, possibly composed of minerals that crystallized or were cemented together when fluids (perhaps water) circulated through the fractures. On the right side of the sub image is a valley filled with dark material and a central, bright ridge. If the valley was carved by liquid water, then this ridge may mark a former stream channel where coarse-grained sediment was deposited, which has survived erosion more effectively than the finer-grained sediment in the valley outside the channel. Similar “inverted channel” deposits are visible elsewhere on Mars, and some examples in the southern highlands have been inferred to contain chloride salts (similar to table salt). The color and texture of the possible inverted channels in this image are similar to those inferred to contain chlorides, which may have been deposited when salty water evaporated. This image is located about halfway between Ariadnes Colles and the source of Ma'adim Vallis.