The mineralogy of Mars is the chemical composition of rocks and soil that encompass the surface of Mars. Various orbital crafts have used spectroscopic methods to identify the signature of some minerals. The planetary landers performed concrete chemical analysis of the soil in rocks to further identify and confirm the presence of other minerals. The only samples of Martian rocks that are on Earth are in the form of meteorites. The elemental and atmospheric composition along with planetary conditions is essential in knowing what minerals can be formed from these base parts.
The surface geology of Mars is somewhere between the basalt or andesite rocks on Earth. This led to the formation of minerals similar to what is found on Earth. The presence of iron oxide gives the surface the “rust” color that is associated with Mars, the Red Planet. The presence of perchlorate, in high percentages, forms highly saline soils, which could produce liquid water. [1] Chemical alteration of Martian rocks into carbonate and phyllosilicate minerals occurred earlier in Mars history when water was present in large quantities. [2] Orbital instruments and Landers not only identified new minerals but in some cases also confirmed the presence of minerals detected by the others.
Orbital crafts sent to Mars provided data on surface geology mostly through spectroscopy. This data is used to determine possible minerals on the surface, and the types of instruments Landers would need in order to narrow down those minerals.
Mars Global Surveyor
Launched in 1996, it used the Mars Orbiter Camera (MOC), Mars Orbital Laser Altimeter, and Thermal Emission Spectrometer to show layering on the surface, presence of surface ice, and the mineral hematite. The presence of ice over the surface is essential to understanding why certain water bearing minerals are on Mars.
Mars Odyssey
Launched in 2001, although it carried multiple instruments only Thermal Emission Imaging System was designed to look at minerals. This allowed it to detect the presence of quartz, olivine, and hematite.
Mars Express
Launched in 2003 the Visible and Infrared Mineralogical Mapping Spectrometer (OMEGA) observed montmorillonite and localized phyllosilicate minerals. [2]
Mars Reconnaissance Orbiter
Launched in 2005 this orbiter carried multiple instruments which found the mineralogy to be dominated by mafic minerals such as olivine, mica, pyroxene and smectite clays such as kaolinite. The HiRISE was used in determining the landing site for the Phoenix Lander. Using the CTX (camera) and CRISM instruments it was able to find phyllosilicate minerals, carbonate minerals, and oxides. The SHARAD was used to detect carbonate dust layers. [3]
To date, the only method planetary scientists have used to carry out experiments on the Martian surface has been to send probes to it. The successful missions are able to carry out experiments that directly observe the composition of Martian soil and rocks. They are the key to verifying our observations of minerals, although currently they are limited to the uppermost area of the surface.
Mars Pathfinder
Mars Exploration Rover Mission
Launched in 2003 it contained two separate rovers the Spirit rover and the Opportunity rover.
Spirit One of its instruments the Mössbauer spectrometer (MIMOS II) was designed to look at the iron bearing minerals on mars. It is responsible for determining the presence of many specific iron oxides, which give the planet a red color. [4]
Opportunity Using the Mini-TES it was able to detect the presence of some calcium and magnesium rich sulfate minerals. It also found feldspar, jarosite, pigeonite, clinopyroxene, and maskelynite along with detecting the presence of minerals found by the orbiters and other rovers. [5]
Phoenix Lander
Most noted for landing in a polar region, it carries the WCL (Wet Chemistry Laboratory), which is a part of the MECA (Microscopy, Electrochemistry, and Conductivity Analyzer) instrument suite. It is responsible for identifying perchlorate salts, and various cations such as magnesium, sodium, calcium, and potassium. Along with TEGA it showed the presence of calcium carbonate, and minute traces of methane. Due to the analytical limits of MECA, the Phoenix was unable to determine the sulfur-based minerals detected by the Opportunity. [6]
NASA's Mars Exploration Rover (MER) mission was a robotic space mission involving two Mars rovers, Spirit and Opportunity, exploring the planet Mars. It began in 2003 with the launch of the two rovers to explore the Martian surface and geology; both landed on Mars at separate locations in January 2004. Both rovers far outlived their planned missions of 90 Martian solar days: MER-A Spirit was active until March 22, 2010, while MER-B Opportunity was active until June 10, 2018.
Gusev is a crater on the planet Mars and is located at 14.5°S 175.4°E and is in the Aeolis quadrangle. The crater is about 166 kilometers in diameter and formed approximately three to four billion years ago. It was named after Russian astronomer Matvey Gusev (1826–1866) in 1976.
Meridiani Planum (alternatively Terra Meridiani) is a large plain straddling the equator of Mars. The plain sits on top of an enormous body of sediments that contains a lot of bound water. The iron oxide in the spherules is crystalline (grey) hematite (Fe2O3).
Sinus Meridiani is an albedo feature on Mars stretching east-west just south of the planet's equator. It was named by the French astronomer Camille Flammarion in the late 1870s.
Martian spherules (also known as hematite spherules, blueberries, & Martian blueberries) are small spherules (roughly spherical pebbles) that are rich in an iron oxide (grey hematite, α-Fe2O3) and are found at Meridiani Planum (a large plain on Mars) in exceedingly large numbers.
The Thermal Emission Imaging System (THEMIS) is a camera on board the 2001 Mars Odyssey orbiter. It images Mars in the visible and infrared parts of the electromagnetic spectrum in order to determine the thermal properties of the surface and to refine the distribution of minerals on the surface of Mars as determined by the Thermal Emission Spectrometer (TES). Additionally, it helps scientists to understand how the mineralogy of Mars relates to its landforms, and it can be used to search for thermal hotspots in the Martian subsurface.
The Columbia Hills are a range of low hills inside Gusev crater on Mars. They were observed by the Mars Exploration Rover Spirit when it landed within the crater in 2004. They were promptly given an unofficial name by NASA since they were the most striking nearby feature on the surface. The hills lie approximately 3 kilometres (1.9 mi) away from the rover's original landing position. The range is named to memorialize the Space Shuttle Columbia disaster. On February 2, 2004, the individual peaks of the Columbia Hills were named after the seven astronauts who died in the disaster. Spirit spent a few years exploring the Columbia Hills until it ceased to function in 2010. It was also considered a potential landing site for the Mars 2020 Perseverance rover, before the selection of Jezero crater in November 2018.
NASA's 2003 Mars Exploration Rover Mission has amassed an enormous amount of scientific information related to the Martian geology and atmosphere, as well as providing some astronomical observations from Mars. This article covers information gathered by the Opportunity rover during the initial phase of its mission. Information on science gathered by Spirit can be found mostly in the Spirit rover article.
The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) was a visible-infrared spectrometer aboard the Mars Reconnaissance Orbiter searching for mineralogic indications of past and present water on Mars. The CRISM instrument team comprised scientists from over ten universities and was led by principal investigator Scott Murchie. CRISM was designed, built, and tested by the Johns Hopkins University Applied Physics Laboratory.
In inorganic chemistry, mineral hydration is a reaction which adds water to the crystal structure of a mineral, usually creating a new mineral, commonly called a hydrate.
The formation of carbonates on Mars have been suggested based on evidence of the presence of liquid water and atmospheric carbon dioxide in the planet's early stages. Moreover, due to their utility in registering changes in environmental conditions such as pH, temperature, fluid composition, carbonates have been considered as a primary target for planetary scientists' research. However, since their first detection in 2008, the large deposits of carbonates that were once expected on Mars have not been found, leading to multiple potential explanations that can explain why carbonates did not form massively on the planet.
Mawrth Vallis is a valley on Mars, located in the Oxia Palus quadrangle at 22.3°N, 343.5°E with an elevation approximately two kilometers below datum. Situated between the southern highlands and northern lowlands, the valley is a channel formed by massive flooding which occurred in Mars’ ancient past. It is an ancient water outflow channel with light-colored clay-rich rocks.
The surface color of the planet Mars appears reddish from a distance because of rusty atmospheric dust. From close up, it looks more of a butterscotch, and other common surface colors include golden, brown, tan, and greenish, depending on minerals.
Martian regolith is the fine blanket of unconsolidated, loose, heterogeneous superficial deposits covering the surface of Mars. The term Martian soil typically refers to the finer fraction of regolith. So far, no samples have been returned to Earth, the goal of a Mars sample-return mission, but the soil has been studied remotely with the use of Mars rovers and Mars orbiters. Its properties can differ significantly from those of terrestrial soil, including its toxicity due to the presence of perchlorates.
The Aeolis quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Aeolis quadrangle is also referred to as MC-23 . The Aeolis quadrangle covers 180° to 225° W and 0° to 30° south on Mars, and contains parts of the regions Elysium Planitia and Terra Cimmeria. A small part of the Medusae Fossae Formation lies in this quadrangle.
The Margaritifer Sinus quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Margaritifer Sinus quadrangle is also referred to as MC-19. The Margaritifer Sinus quadrangle covers the area from 0° to 45° west longitude and 0° to 30° south latitude on Mars. Margaritifer Sinus quadrangle contains Margaritifer Terra and parts of Xanthe Terra, Noachis Terra, Arabia Terra, and Meridiani Planum.
Almost all water on Mars today exists as polar permafrost ice, though it also exists in small quantities as vapor in the atmosphere.
To date, interplanetary spacecraft have provided abundant evidence of water on Mars, dating back to the Mariner 9 mission, which arrived at Mars in 1971. This article provides a mission by mission breakdown of the discoveries they have made. For a more comprehensive description of evidence for water on Mars today, and the history of water on that planet, see Water on Mars.
The composition of Mars covers the branch of the geology of Mars that describes the make-up of the planet Mars.
Astropedology is the study of very ancient paleosols and meteorites relevant to the origin of life and different planetary soil systems. It is a branch of soil science (pedology) concerned with soils of the distant geologic past and of other planetary bodies to understand our place in the universe. A geologic definition of soil is “a material at the surface of a planetary body modified in place by physical, chemical or biological processes”. Soils are sometimes defined by biological activity but can also be defined as planetary surfaces altered in place by biologic, chemical, or physical processes. By this definition, the question for Martian soils and paleosols becomes, were they alive? Astropedology symposia are a new focus for scientific meetings on soil science. Advancements in understanding the chemical and physical mechanisms of pedogenesis on other planetary bodies in part led the Soil Science Society of America (SSSA) in 2017 to update the definition of soil to: "The layer(s) of generally loose mineral and/or organic material that are affected by physical, chemical, and/or biological processes at or near the planetary surface and usually hold liquids, gases, and biota and support plants". Despite our meager understanding of extraterrestrial soils, their diversity may raise the question of how we might classify them, or formally compare them with our Earth-based soils. One option is to simply use our present soil classification schemes, in which case many extraterrestrial soils would be Entisols in the United States Soil Taxonomy (ST) or Regosols in the World Reference Base for Soil Resources (WRB). However, applying an Earth-based system to such dissimilar settings is debatable. Another option is to distinguish the (largely) biotic Earth from the abiotic Solar System, and include all non-Earth soils in a new Order or Reference Group, which might be tentatively called Astrosols.
