PIA17944-MarsCuriosityRover-AfterCrossingDingoGapSanddune-20140209

Martian soil is the fine

regolith Regolith () is a blanket of unconsolidated, loose, heterogeneous superficial deposits covering solid rock. It includes dust, broken rocks, and other related materials and is present on Earth, the Moon, Mars, some asteroids, and other terrestr ...

(a blanket of unconsolidated, loose, heterogeneous superficial deposits covering solid rock) found on the surface of

Mars Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin at ...

. Its properties can differ significantly from those of terrestrial

soil Soil, also commonly referred to as earth or dirt Dirt is an unclean matter, especially when in contact with a person's clothes, skin, or possessions. In such cases, they are said to become dirty. Common types of dirt include: * Debri ...

, including its toxicity due to the presence of

perchlorate A perchlorate is a chemical compound containing the perchlorate ion, . The majority of perchlorates are commercially produced salts. They are mainly used as oxidizers for pyrotechnic devices and to control static electricity in food packaging. Per ...

s. 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 A Mars sample-return (MSR) mission is a proposed mission to collect rock and dust samples on Mars and return them to Earth. Such a mission would allow more extensive analysis than that allowed by onboard sensors. The three most recent concept ...

, but the soil has been studied remotely with the use of

Mars rover A Mars rover is a motor vehicle designed to travel on the surface of Mars. Rovers have several advantages over stationary landers: they examine more territory, they can be directed to interesting features, they can place themselves in sunny pos ...

s and Mars orbiters. On Earth, the term "soil" usually includes organic content. In contrast, planetary scientists adopt a functional definition of soil to distinguish it from rocks. Rocks generally refer to 10 cm scale and larger materials (e.g., fragments,

breccia Breccia () is a rock composed of large angular broken fragments of minerals or rocks cemented together by a fine-grained matrix. The word has its origins in the Italian language, in which it means "rubble". A breccia may have a variety of ...

, and exposed outcrops) with high thermal inertia, with areal fractions consistent with the Viking Infrared Thermal Mapper (IRTM) data, and immobile under current aeolian (wind) conditions. Consequently, rocks classify as grains exceeding the size of cobbles on the Wentworth scale. This approach enables agreement across Martian remote sensing methods that span the electromagnetic spectrum from gamma to

radio waves Radio waves are a type of electromagnetic radiation with the longest wavelengths in the electromagnetic spectrum, typically with frequencies of 300 gigahertz ( GHz) and below. At 300 GHz, the corresponding wavelength is 1 mm (s ...

. ‘‘Soil’’ refers to all other, typically unconsolidated, material including those sufficiently fine-grained to be mobilized by wind. Soil consequently encompasses a variety of

components identified at landing sites. Typical examples include:

bedform A bedform is a geological feature that develops at the interface of fluid and a moveable bed, the result of bed material being moved by fluid flow. Examples include ripples and dunes on the bed of a river. Bedforms are often preserved in the ro ...

(a feature that develops at the interface of fluid and a moveable bed such as ripples and dunes),

clasts Clastic rocks are composed of fragments, or clasts, of pre-existing minerals and rock. A clast is a fragment of geological detritus,Essentials of Geology, 3rd Ed, Stephen Marshak, p. G-3 chunks, and smaller grains of rock broken off other rocks ...

(fragments of pre-existing minerals and rock such as sediment deposits),

concretion A concretion is a hard, compact mass of matter formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary rock or soil. Concretions are often ovoid or spherical in shape, although irregular ...

s, drift,

dust Dust is made of fine particles of solid matter. On Earth, it generally consists of particles in the atmosphere that come from various sources such as soil lifted by wind (an aeolian process), volcanic eruptions, and pollution. Dust in ho ...

, rocky fragments, and

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class o ...

. The functional definition reinforces a recently proposed generic definition of soil on terrestrial bodies (including asteroids and

satellite A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioi ...

s) as an unconsolidated and chemically weathered surficial layer of fine-grained

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2 ...

or organic material exceeding centimeter scale thickness, with or without coarse elements and cemented portions. Martian dust generally connotes even finer materials than Martian soil, the fraction which is less than 30 micrometres in diameter. Disagreement over the significance of soil's definition arises due to the lack of an integrated concept of soil in the literature. The pragmatic definition "medium for plant growth" has been commonly adopted in the planetary science community but a more complex definition describes soil as "(bio)geochemically/physically altered material at the surface of a planetary body that encompasses surficial extraterrestrial telluric deposits." This definition emphasizes that soil is a body that retains information about its environmental history and that does not need the presence of life to form.

Toxicity

Martian soil is toxic, due to relatively high concentrations of

compounds containing

chlorine Chlorine is a chemical element with the symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine i ...

. Elemental chlorine was first discovered during localised investigations by

''Sojourner'', and has been confirmed by ''Spirit'', ''Opportunity'' and ''Curiosity''. The ''

Mars Odyssey ''2001 Mars Odyssey'' is a robotic spacecraft orbiting the planet Mars. The project was developed by NASA, and contracted out to Lockheed Martin, with an expected cost for the entire mission of US$297 million. Its mission is to use spectro ...

'' orbiter has also detected

s across the surface of the planet. The NASA ''Phoenix'' lander first detected chlorine-based compounds such as

calcium perchlorate Calcium perchlorate is classified as a metal perchlorate salt with the molecular formula . It is an inorganic compound that is a yellow-white crystalline solid in appearance. As a strong oxidizing agent, it reacts with reducing agents when heat ...

. The levels detected in the Martian soil are around 0.5%, which is a level considered toxic to humans. These compounds are also toxic to plants. A 2013 terrestrial study found that a similar level of concentration to that found on Mars (0.5 g per liter) caused: * a significant decline in the chlorophyll content in plant leaves, * reduction in the oxidizing power of plant roots * reduction in the size of the plant both above and below ground * an accumulation of concentrated perchlorates in the leaves The report noted that one of the types of plant studied, ''

Eichhornia crassipes ''Pontederia crassipes'' (formerly ''Eichhornia crassipes''), commonly known as common water hyacinth is an aquatic plant native to South America, naturalized throughout the world, and often invasive outside its native range. There is evidence that some bacterial lifeforms are able to overcome perchlorates by physiological adaptations to increasing perchlorate concentrations, and some even live off them. However, the added effect of the high levels of UV reaching the surface of Mars breaks the molecular bonds, creating even more dangerous chemicals which in lab tests on Earth were shown to be more lethal to bacteria than the perchlorates alone.

Dust hazard

PIA25361-MarsPerseveranceRover-WindLiftsDustCloud-20210618

The potential danger to human health of the fine Martian dust has long been recognized by

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program ...

. A 2002 study warned about the potential threat, and a study was carried out using the most common silicates found on Mars:

olivine The mineral olivine () is a magnesium iron silicate with the chemical formula . It is a type of nesosilicate or orthosilicate. The primary component of the Earth's upper mantle, it is a common mineral in Earth's subsurface, but weathers quickl ...

, pyroxene and

feldspar Feldspars are a group of rock-forming aluminium tectosilicate minerals, also containing other cations such as sodium, calcium, potassium, or barium. The most common members of the feldspar group are the ''plagioclase'' (sodium-calcium) felds ...

. It found that the dust reacted with small amounts of water to produce highly reactive molecules that are also produced during the mining of quartz and known to produce

lung disease The lungs are the primary organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side ...

in miners on Earth, including cancer (the study also noted that lunar dust may be worse). Following on from this, since 2005 NASA's Mars Exploration Program Analysis Group (MEPAG) has had a goal to determine the possible toxic effects of the dust on humans. In 2010, the group noted that although the ''Phoenix'' lander and the rovers ''Spirit'' and ''Opportunity'' had contributed to answering this question, none of the instruments have been suitable for measuring the particular

carcinogen A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis (the formation of cancer). This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Several radioactive subs ...

s that are of concern. The

Mars 2020 Mars 2020 is a Mars rover mission forming part of NASA's Mars Exploration Program that includes the rover '' Perseverance'', the small robotic, coaxial helicopter '' Ingenuity'', and associated delivery vehicles. Mars 2020 was launched from ...

rover is an astrobiology mission that will also make measurements to help designers of a future human expedition understand any hazards posed by Martian dust. It employs the following related instruments: * MEDA, a set of atmospheric sensors that measure various things including radiation, and dust size and shape. *

PIXL PixL is an independent American television channel that broadcasts commercial-free films and miniseries targeted at families. The network debuted on December 7, 2010 on the Dish Network DISH Network Corporation (DISH, an acronym for DIgita ...

, an

X-ray fluorescence X-ray fluorescence (XRF) is the emission of characteristic "secondary" (or fluorescent) X-rays from a material that has been excited by being bombarded with high-energy X-rays or gamma rays. The phenomenon is widely used for elemental analysis ...

spectrometer A spectrometer () is a scientific instrument used to separate and measure spectral components of a physical phenomenon. Spectrometer is a broad term often used to describe instruments that measure a continuous variable of a phenomenon where the ...

to determine the fine scale elemental composition of Martian surface materials. *

SHERLOC Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) is an ultraviolet Raman spectrometer that uses fine-scale imaging and an ultraviolet (UV) laser to determine fine-scale mineralogy, and detect orga ...

, an ultraviolet

Raman spectrometer Raman spectroscopy () (named after Indian physicist C. V. Raman) is a spectroscopic technique typically used to determine vibrational modes of molecules, although rotational and other low-frequency modes of systems may also be observed. Raman sp ...

that uses fine-scale imaging and an ultraviolet (UV) laser to determine fine-scale mineralogy The Mars 2020 rover mission will cache samples that could potentially be retrieved by a future mission for their transport to Earth. Any questions about dust toxicity that have not already been answered ''

in situ ''In situ'' (; often not italicized in English) is a Latin phrase that translates literally to "on site" or "in position." It can mean "locally", "on site", "on the premises", or "in place" to describe where an event takes place and is used in ...

'' can then be tackled by labs on Earth.

Observations

PIA16572-MarsCuriosityRover-RoverSoils-20121203

Mars is covered with vast expanses of sand and dust and its surface is littered with rocks and boulders. The dust is occasionally picked up in vast planet-wide

dust storm A dust storm, also called a sandstorm, is a meteorological phenomenon common in arid and semi-arid regions. Dust storms arise when a gust front or other strong wind blows loose sand and dirt from a dry surface. Fine particles are transp ...

s. Mars dust is very fine, and enough remains suspended in the atmosphere to give the sky a reddish hue. The reddish

hue In color theory, hue is one of the main properties (called color appearance parameters) of a color, defined technically in the CIECAM02 model as "the degree to which a stimulus can be described as similar to or different from stimuli that ...

is due to rusting iron minerals presumably formed a few billion years ago when Mars was warm and wet, but now that Mars is cold and dry, modern rusting may be due to a

superoxide In chemistry, a superoxide is a compound that contains the superoxide ion, which has the chemical formula . The systematic name of the anion is dioxide(1−). The reactive oxygen ion superoxide is particularly important as the product of t ...

that forms on minerals exposed to ultraviolet rays in sunlight. The sand is believed to move only slowly in the Martian winds due to the very low density of the atmosphere in the present epoch. In the past, liquid water flowing in gullies and river valleys may have shaped the Martian regolith. Mars researchers are studying whether

groundwater sapping Groundwater sapping is a geomorphic erosion process that results in the headward migration of channels in response to near constant fluid discharge at a fixed point. The consistent flow of water displaces fine sediments which physically and chemical ...

is shaping the Martian regolith in the present epoch, and whether carbon dioxide hydrates exist on Mars and play a role. PIA16217-MarsCuriosityRover-1stXRayView-20121017

PIA16217-MarsCuriosityRover-1stXRayView-20121017

It is believed that large quantities of water and carbon dioxide ices remain frozen within the regolith in the equatorial parts of Mars and on its surface at higher latitudes. According to the High Energy Neutron Detector of the

satellite the water content of Martian regolith is up to 5% by weight. The presence of

, which is an easily weatherable primary mineral, has been interpreted to mean that physical rather than chemical weathering processes currently dominate on

. High concentrations of ice in soils are thought to be the cause of accelerated soil creep, which forms the rounded " softened terrain" characteristic of the Martian midlatitudes. In June 2008, the ''Phoenix'' lander returned data showing Martian soil to be slightly alkaline and containing vital nutrients such as

magnesium Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ta ...

sodium Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable ...

potassium Potassium is the chemical element with the symbol K (from Neo-Latin ''kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmosph ...

and

chloride The chloride ion is the anion (negatively charged ion) Cl−. It is formed when the element chlorine (a halogen) gains an electron or when a compound such as hydrogen chloride is dissolved in water or other polar solvents. Chloride sa ...

, all of which are ingredients for living organisms to grow on Earth. Scientists compared the soil near Mars' north pole to that of backyard gardens on Earth, and concluded that it could be suitable for growth of plants. However, in August 2008, the Phoenix Lander conducted simple chemistry experiments, mixing water from Earth with Martian soil in an attempt to test its pH, and discovered traces of the

salt Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quant ...

, while also confirming many scientists' theories that the Martian surface was considerably basic, measuring at 8.3. The presence of the perchlorate makes Martian soil more exotic than previously believed (see

Toxicity Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a subs ...

section). Further testing was necessary to eliminate the possibility of the perchlorate readings being caused by terrestrial sources, which at the time were thought could have migrated from the spacecraft either into samples or the instrumentation. However, each new lander has confirmed their presence in the soil locally and the ''

'' orbiter confirmed they are spread globally across the entire surface of the planet. In 1999 the

Mars Pathfinder ''Mars Pathfinder'' (''MESUR Pathfinder'') is an American robotic spacecraft that landed a base station with a roving probe on Mars in 1997. It consisted of a lander, renamed the Carl Sagan Memorial Station, and a lightweight, wheeled robot ...

rover performed an indirect electrostatics measurement of the Martian regolith. The Wheel Abrasion Experiment (WAE) was designed with fifteen metal samples and film insulators mounted on the wheel to reflect sunlight to a photovoltaic sensor. Lander cameras showed dust accumulating on the wheels as the rover moved and the WAE detected a drop in the amount of light hitting the sensor. It is believed that the dust may have acquired an electrostatic charge as the wheels rolled across the surface causing the dust to adhere to the film surface. While our understanding of Martian soils is extremely rudimentary, their diversity may raise the question of how we might compare them with our Earth-based soils. Applying an Earth-based system is largely debatable but a simple option is to distinguish the (largely) biotic Earth from the

abiotic In biology and ecology, abiotic components or abiotic factors are non-living chemical and physical parts of the environment that affect living organisms and the functioning of ecosystems. Abiotic factors and the phenomena associated with them under ...

Solar System, and include all non-Earth soils in a new

World Reference Base for Soil Resources The World Reference Base for Soil Resources (WRB) is an international soil classification system for naming soils and creating legends for soil maps. The currently valid version is the fourth edition 2022. It is edited by a working group of the In ...

Reference Group or

USDA soil taxonomy USDA soil taxonomy (ST) developed by the United States Department of Agriculture and the National Cooperative Soil Survey provides an elaborate classification of soil types according to several parameters (most commonly their properties) and in ...

Order, which might be tentatively called Astrosols. On October 17, 2012 ( ''Curiosity'' rover at " Rocknest"), the first X-ray diffraction analysis of Martian soil was performed. The results revealed the presence of several minerals, including

, pyroxenes and

, and suggested that the Martian soil in the sample was similar to the "weathered basaltic soils" of Hawaiian volcanoes. Hawaiian volcanic ash has been used as

Martian regolith simulant Martian regolith simulant (or Martian soil simulant) is a terrestrial material that is used to simulate the chemical and mechanical properties of Martian regolith for research, experiments and prototype testing of activities related to Martian r ...

by researchers since 1998. In December 2012, scientists working on the

Mars Science Laboratory Mars Science Laboratory (MSL) is a robotic space probe mission to Mars launched by NASA on November 26, 2011, which successfully landed ''Curiosity'', a Mars rover, in Gale Crater on August 6, 2012. The overall objectives include investigati ...

mission announced that an extensive soil analysis of Martian soil performed by the ''Curiosity'' rover showed evidence of water molecules, sulphur and

, as well as hints of

organic compounds In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The s ...

. However,

terrestrial Terrestrial refers to things related to land or the planet Earth. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on or near the ground, as opposed to ...

contamination, as the source of the organic compounds, could not be ruled out. On September 26, 2013, NASA scientists reported the

''Curiosity'' rover detected "abundant, easily accessible"

water Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living ...

(1.5 to 3 weight percent) in soil samples at the Rocknest region of Aeolis Palus in

Gale Crater Gale is a crater, and probable dry lake, at in the northwestern part of the Aeolis quadrangle on Mars. It is in diameter and estimated to be about 3.5–3.8 billion years old. The crater was named after Walter Frederick Gale, an amateur ast ...

. In addition, NASA reported that the ''Curiosity'' rover found two principal soil types: a fine-grained mafic type and a locally derived, coarse-grained felsic type. The mafic type, similar to other Martian soils and Martian dust, was associated with hydration of the amorphous phases of the soil. Also, perchlorates, the presence of which may make detection of life-related organic molecules difficult, were found at the Curiosity rover landing site (and earlier at the more polar site of the

Phoenix lander ''Phoenix'' was an uncrewed space probe that landed on the surface of Mars on May 25, 2008, and operated until November 2, 2008. ''Phoenix'' was operational on Mars for sols ( days). Its instruments were used to assess the local habitabilit ...

) suggesting a "global distribution of these salts". NASA also reported that Jake M rock, a rock encountered by ''Curiosity'' on the way to Glenelg, was a mugearite and very similar to terrestrial mugearite rocks. On April 11, 2019, NASA announced that the ''Curiosity'' rover on Mars drilled into, and closely studied, a " clay-bearing unit" which, according to the rover Project Manager, is a "major milestone" in ''Curiosity'' journey up Mount Sharp. PIA23138-MarsCuriosityRover-Drills-ClayBearingUnit-20190406

PIA23138-MarsCuriosityRover-Drills-ClayBearingUnit-20190406

Humans will need in situ resources for colonising Mars. That demands an understanding of the local unconsolidated bulk sediment, but the classification of such sediment remains a work in progress. Too little of the entire Martian surface is known to draw a sufficiently representative picture. In the meantime, it is correct to better use the term soil for indicating unconsolidated sediment of Mars.

Atmospheric dust

PIA24039-MarsCuriosityRover-DustDevil-20200809

MarsDustDevi-AmazonisPlanitia-MGS-MOC-20010401-E03-00938

Similarly sized dust will settle from the thinner Martian atmosphere sooner than it would on Earth. For example, the dust suspended by the 2001 global dust storms on Mars only remained in the Martian atmosphere for 0.6 years, while the dust from

Mount Pinatubo Mount Pinatubo is an active stratovolcano in the Zambales Mountains, located on the tripoint boundary of the Philippine provinces of Zambales, Tarlac and Pampanga, all in Central Luzon on the northern island of Luzon. Its eruptive histor ...

took about two years to settle. However, under current Martian conditions, the mass movements involved are generally much smaller than on Earth. Even the 2001 global dust storms on Mars moved only the equivalent of a very thin dust layer – about 3 µm thick if deposited with uniform thickness between 58° north and south of the equator. Dust deposition at the two rover sites has proceeded at a rate of about the thickness of a grain every 100 sols. The difference in the concentration of dust in Earth's atmosphere and that of Mars stems from a key factor. On Earth, dust that leaves atmospheric suspension usually gets aggregated into larger particles through the action of soil moisture or gets suspended in oceanic waters. It helps that most of Earth's surface is covered by liquid water. Neither process occurs on Mars, leaving deposited dust available for suspension back into the Martian atmosphere. In fact, the composition of Martian atmospheric dust – very similar to surface dust – as observed by the

Mars Global Surveyor ''Mars Global Surveyor'' (MGS) was an American robotic space probe developed by NASA's Jet Propulsion Laboratory and launched November 1996. MGS was a global mapping mission that examined the entire planet, from the ionosphere down through t ...

Thermal Emission Spectrometer, may be volumetrically dominated by composites of plagioclase feldspar and zeolite which can be mechanically derived from Martian basaltic rocks without chemical alteration. Observations of the Mars Exploration Rovers’ magnetic dust traps suggest that about 45% of the elemental iron in atmospheric dust is maximally oxidized () and that nearly half exists in titanomagnetite,Goetz et al. (2007)
Seventh Mars Conference
/ref> both consistent with mechanical derivation of dust with aqueous alteration limited to just thin films of water. Collectively, these observations support the absence of water-driven dust aggregation processes on Mars. Furthermore, wind activity dominates the surface of Mars at present, and the abundant dune fields of Mars can easily yield particles into atmospheric suspension through effects such as larger grains disaggregating fine particles through collisions. The Martian atmospheric dust particles are generally 3 µm in diameter. It is important to note that while the atmosphere of Mars is thinner, Mars also has a lower gravitational acceleration, so the size of particles that will remain in suspension cannot be estimated with atmospheric thickness alone. Electrostatic and

van der Waals forces In molecular physics, the van der Waals force is a distance-dependent interaction between atoms or molecules. Unlike ionic or covalent bonds, these attractions do not result from a chemical electronic bond; they are comparatively weak and th ...

acting among fine particles introduce additional complexities to calculations. Rigorous modeling of all relevant variables suggests that 3 µm diameter particles can remain in suspension indefinitely at most wind speeds, while particles as large as 20 µm diameter can enter suspension from rest at surface wind turbulence as low as 2 ms⁻¹ or remain in suspension at 0.8 ms⁻¹. In July 2018, researchers reported that the largest single source of dust on the planet

comes from the

Medusae Fossae Formation The Medusae Fossae Formation is a large geological formation of probable volcanic origin on the planet Mars. It is named for the Medusa of Greek mythology. "Fossae" is Latin for "trenches". The formation is a collection of soft, easily eroded de ...

Research on Earth

Research on

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

is currently limited to using Martian soil simulants, which are based on the analysis from the various

spacecraft A spacecraft is a vehicle or machine designed to fly in outer space. A type of artificial satellite, spacecraft are used for a variety of purposes, including communications, Earth observation, meteorology, navigation, space colonization, p ...

. These are a terrestrial material that is used to simulate the chemical and mechanical properties of

Martian Mars, the fourth planet from the Sun, has appeared as a setting in works of fiction since at least the mid-1600s. It became the most popular celestial object in fiction in the late 1800s as the Moon was evidently lifeless. At the time, the pr ...

for research, experiments and prototype testing of activities related to Martian soil such as dust mitigation of transportation equipment, advanced life support systems and in-situ resource utilization. A number of

Mars sample return A Mars sample-return (MSR) mission is a proposed mission to collect rock and dust samples on Mars and sample-return mission, return them to Earth. Such a mission would allow more extensive analysis than that allowed by onboard sensors. The thr ...

missions are being planned, which would allow actual Martian soil to be returned to

for more advanced analysis than is possible in situ on the surface of

. This should allow even more accurate simulants. The first of these missions is a multi-part mission beginning with the

lander. This will collect samples over a long period. A second lander will then gather the samples and return them to

Gallery

Image:PIA08440-Mars Rover Spirit-Volcanic Rock Fragment.jpg, Martian sand and boulders photographed by NASA's

Mars Exploration Rover 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 ...

''Spirit'' (April 13, 2006). Image:PIA17062-MarsCuriosityRover-HottahRockOutcrop-20120915.jpg, " Hottah"

rock outcrop An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth. Features Outcrops do not cover the majority of the Earth's land surface because in most places the bedrock or superficia ...

close-up3D
(September 12, 2012). Image:PIA16193-MarsCuriosityRover-ScoffmarkInSand-2011004.jpg, " Rocknest" sand on Mars – scoffmark made by the ''

Curiosity Curiosity (from Latin '' cūriōsitās'', from ''cūriōsus'' "careful, diligent, curious", akin to ''cura'' "care") is a quality related to inquisitive thinking such as exploration, investigation, and learning, evident by observation in humans ...

'' rover ( MAHLI, October 4, 2012). Image:PIA16452-MarsCuriosityRover-Rocknest3Rock-20121005.jpg, " Rocknest 3" rock on Mars – as viewed by the MastCam on ''

'' (October 5, 2012). Image:PIA18590-MarsCuriosityRover-HiddenValleyTracks-20140804.jpg, Tracks of the ''

'' rover in the sands of " Hidden Valley" (August 4, 2014). Image:MarsCuriosityRover-HiddenValley-WheelCloseup-20140806.jpg, Wheel of the ''

'' rover partially submerged in sand at Hidden Valley (August 6, 2014). Image:PIA21143 - Sand Moving Under Curiosity, One Day to Next, Animation.gif, Sand moving on Mars – as viewed by ''Curiosity'' (January 23, 2017). Image:PIA22512-Mars-BlueDune-20180624.jpg, Blue dune on Mars
(false colors, blue represents colder areas)
(January 24, 2018). Image:ESP 053894 2295-Mars-BlueDune-EnhancedColor-20180124.jpg, Blue dune on Mars>
(false colors, blue represents colder areas)
(Enhanced color; January 24, 2018) Image:NASA-Mars-$tarTrekFleetLogo-20190612.jpg, Dunes on

look like the '' Star Trek''

Starfleet Starfleet is a fictional organization in the ''Star Trek'' media franchise. Within this fictional universe, Starfleet is a uniformed space force maintained by the United Federation of Planets ("the Federation") as the principal means for conduc ...

emblem.

References

External links

Video (04:32) - Evidence: Water "Vigorously" Flowed On Mars - September, 2012
{{Geography of Mars Mars Missions to Mars Regolith Rocks on Mars Surface features of Mars Water on Mars