Martian soil

Last updated

Curiosity's view of Martian soil and boulders after crossing the "Dingo Gap" sand dune (February 9, 2014; image transformed to Earth-like atmospheric view, original image). PIA17944-MarsCuriosityRover-AfterCrossingDingoGapSanddune-20140209.jpg
Curiosity 's view of Martian soil and boulders after crossing the "Dingo Gap" sand dune (February 9, 2014; image transformed to Earth-like atmospheric view, original image).

Martian soil is the fine regolith (a blanket of unconsolidated, loose, heterogeneous superficial deposits covering solid rock) found on the surface of Mars. Its properties can differ significantly from those of terrestrial soil, including its toxicity due to the presence of perchlorates. 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.

Contents

On Earth, the term "soil" usually includes organic content. [1] In contrast, planetary scientists adopt a functional definition of soil to distinguish it from rocks. [2] Rocks generally refer to 10 cm scale and larger materials (e.g., fragments, breccia, 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. [2] 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. ‘‘Soil’’ refers to all other, typically unconsolidated, material including those sufficiently fine-grained to be mobilized by wind. [2] Soil consequently encompasses a variety of regolith components identified at landing sites. Typical examples include: bedform (a feature that develops at the interface of fluid and a moveable bed such as ripples and dunes), clasts (fragments of pre-existing minerals and rock such as sediment deposits), concretions, drift, dust, rocky fragments, and sand. The functional definition reinforces a recently proposed generic definition of soil on terrestrial bodies (including asteroids and satellites) as an unconsolidated and chemically weathered surficial layer of fine-grained mineral or organic material exceeding centimeter scale thickness, with or without coarse elements and cemented portions. [1]

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

Mars Perseverance rover - wind lifts a massive dust cloud (June 18, 2021) PIA25361-MarsPerseveranceRover-WindLiftsDustCloud-20210618.gif
Mars Perseverance rover - wind lifts a massive dust cloud (June 18, 2021)

Martian soil is toxic, due to relatively high concentrations of perchlorate compounds containing chlorine. [3] Elemental chlorine was first discovered during localised investigations by Mars rover Sojourner, and has been confirmed by Spirit, Opportunity and Curiosity. The Mars Odyssey orbiter has also detected perchlorates across the surface of the planet.

The NASA Phoenix lander first detected chlorine-based compounds such as calcium perchlorate. The levels detected in the Martian soil are around 0.5%, which is a level considered toxic to humans. [4] 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:

The report noted that one of the types of plant studied, Eichhornia crassipes , seemed resistant to the perchlorates and could be used to help remove the toxic salts from the environment, although the plants themselves would end up containing a high concentration of perchlorates as a result. [5] There is evidence that some bacterial lifeforms are able to overcome perchlorates [6] [7] by physiological adaptations to increasing perchlorate concentrations, [8] and some even live off them. [9] 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. [10]

Dust hazard

The InSight lander at its mission start and end having been covered by Martian dust eventually rendering it inoperable PIA25287-MarsInSightLander-BeforeAfterDustySelfies-20220523.gif
The InSight lander at its mission start and end having been covered by Martian dust eventually rendering it inoperable

The potential danger to human health of the fine Martian dust has long been recognized by NASA. A 2002 study warned about the potential threat, and a study was carried out using the most common silicates found on Mars: olivine, pyroxene and feldspar. 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 in miners on Earth, including cancer (the study also noted that lunar dust may be worse). [11]

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 carcinogens that are of concern. [12] The Mars 2020 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:

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 can then be tackled by labs on Earth.

Observations

Comparison of Soils on Mars - Samples by Curiosity, Opportunity, and Spirit rovers (December 3, 2012). (SiO2 and FeO are divided by 10, and Ni, Zn, and Br are multiplied by 100.) PIA16572-MarsCuriosityRover-RoverSoils-20121203.jpg
Comparison of Soils on Mars - Samples by Curiosity , Opportunity , and Spirit rovers (December 3, 2012). (SiO2 and FeO are divided by 10, and Ni, Zn, and Br are multiplied by 100.)
PIA16225-MarsCuriosityRover-ScooperTest-20121008.jpg
PIA16226-MarsCuriosityRover-FirstScoopOfSoil-20121007.jpg
First use of the Curiosity rover's scooper as it sifts a load of sand at "Rocknest" (October 7, 2012)

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 storms. Mars dust is very fine, and enough remains suspended in the atmosphere to give the sky a reddish hue. The reddish hue 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 that forms on minerals exposed to ultraviolet rays in sunlight. [19] 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 is shaping the Martian regolith in the present epoch, and whether carbon dioxide hydrates exist on Mars and play a role.

First X-ray diffraction view of Martian soil - CheMin analysis reveals feldspar, pyroxenes, olivine and more (Curiosity rover at "Rocknest", October 17, 2012). PIA16217-MarsCuriosityRover-1stXRayView-20121017.jpg
First X-ray diffraction view of Martian soil - CheMin analysis reveals feldspar, pyroxenes, olivine and more (Curiosity rover at "Rocknest", October 17, 2012).

It is believed that large quantities of water and carbon dioxide [21] 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 Mars Odyssey satellite the water content of Martian regolith is up to 5% by weight. [22] [23] The presence of olivine, which is an easily weatherable primary mineral, has been interpreted to mean that physical rather than chemical weathering processes currently dominate on Mars. [24] 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, sodium, potassium and chloride, 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. [25] 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 perchlorate, 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 section). [26] 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. [27] However, each new lander has confirmed their presence in the soil locally and the Mars Odyssey orbiter confirmed they are spread globally across the entire surface of the planet. [4]

"Sutton Inlier" soil on Mars - target of ChemCam's laser - Curiosity rover (May 11, 2013) PIA17262-MarsCuriosityRover-SuttonInlierRockLaserTarget-20130511.gif
"Sutton Inlier" soil on Mars - target of ChemCam's laser - Curiosity rover (May 11, 2013)

In 1999 the Mars Pathfinder 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. [28]

While scientific 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 Solar System, and include all non-Earth soils in a new World Reference Base for Soil Resources Reference Group or USDA soil taxonomy Order, which might be tentatively called Astrosols. [29]

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 feldspar, pyroxenes and olivine, and suggested that the Martian soil in the sample was similar to the "weathered basaltic soils" of Hawaiian volcanoes. [20] Hawaiian volcanic ash has been used as Martian regolith simulant by researchers since 1998. [30]

In December 2012, scientists working on the Mars Science Laboratory mission announced that an extensive soil analysis of Martian soil performed by the Curiosity rover showed evidence of water molecules, sulphur and chlorine, as well as hints of organic compounds. [17] [18] [31] However, terrestrial contamination, as the source of the organic compounds, could not be ruled out.

On September 26, 2013, NASA scientists reported the Mars Curiosity rover detected "abundant, easily accessible" water (1.5 to 3 weight percent) in soil samples at the Rocknest region of Aeolis Palus in Gale Crater. [32] [33] [34] [35] [36] [37] 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. [34] [36] [38] The mafic type, similar to other Martian soils and Martian dust, was associated with hydration of the amorphous phases of the soil. [38] 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) suggesting a "global distribution of these salts". [37] 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. [39]

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's journey up Mount Sharp. [40]

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. [41]

Atmospheric dust

Detail of a Marsian dust storm, as viewed from orbit Dust storm co.tif
Detail of a Marsian dust storm, as viewed from orbit
Mars without a dust storm in June 2001 (on left) and with a global dust storm in July 2001 (on right), as seen by Mars Global Surveyor PIA03170 fig1duststroms.jpg
Mars without a dust storm in June 2001 (on left) and with a global dust storm in July 2001 (on right), as seen by Mars Global Surveyor
Mars dust storm in optical depth tau from May to September 2018
(by Mars Climate Sounder)
Difference of dust and water clouds: the yellow cloud at the bottom center of the image is a large dust cloud, the other white clouds are water clouds. PIA23513-Mars-DustTower-20101130.jpg
Difference of dust and water clouds: the yellow cloud at the bottom center of the image is a large dust cloud, the other white clouds are water clouds.

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 took about two years to settle. [42] 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. [42] Dust deposition at the two rover sites has proceeded at a rate of about the thickness of a grain every 100 sols. [43]

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. [44] In fact, the composition of Martian atmospheric dust – very similar to surface dust – as observed by the Mars Global Surveyor Thermal Emission Spectrometer, may be volumetrically dominated by composites of plagioclase feldspar and zeolite [45] 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 (Fe3+) and that nearly half exists in titanomagnetite, [46] both consistent with mechanical derivation of dust with aqueous alteration limited to just thin films of water. [47] 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. [48]

The Martian atmospheric dust particles are generally 3 µm in diameter. [49] 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 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. [43]

In July 2018, researchers reported that the largest single source of dust on the planet Mars comes from the Medusae Fossae Formation. [50]

Dust devils
PIA24039-MarsCuriosityRover-DustDevil-20200809.gif
Dust devil on Mars as viewed by the Curiosity rover
The Serpent Dust Devil on Mars PIA15116.jpg
A 30 meter wide and 800 meter high dust devil. Dust devils of 20 kilometer height have been observed.
Dust Devil with Labels.JPG
Martian Dust Devil Trails.jpg
Dust devils cause twisting dark trails on the Martian surface

Research on Earth

A small pile of JSC MARS-1A soil simulant Martian regolith simulant - pile.JPG
A small pile of JSC MARS-1A soil simulant

Research on Earth is currently limited to using Martian soil simulants, such as the MGS-1 simulant produced by Exolith Lab, [52] which are based on the analysis from the various Mars spacecraft. These are 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 soil such as dust mitigation of transportation equipment, advanced life support systems and in-situ resource utilization.

A number of Mars sample return missions are being planned, which would allow actual Martian soil to be returned to Earth for more advanced analysis than is possible in situ on the surface of Mars. This should allow even more accurate simulants. The first of these missions is a multi-part mission beginning with the Mars 2020 lander. This will collect samples over a long period. A second lander will then gather the samples and return them to Earth.

See also

Related Research Articles

<span class="mw-page-title-main">Regolith</span> A layer of loose, heterogeneous superficial deposits covering solid rock

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 terrestrial planets and moons.

<span class="mw-page-title-main">Mars Exploration Rover</span> NASA mission to explore Mars via two rovers

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.

<i>Phoenix</i> (spacecraft) NASA Mars 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 157 sols. Its instruments were used to assess the local habitability and to research the history of water on Mars. The mission was part of the Mars Scout Program; its total cost was $420 million, including the cost of launch.

<span class="mw-page-title-main">Life on Mars</span> Scientific assessments on the microbial habitability of Mars

The possibility of life on Mars is a subject of interest in astrobiology due to the planet's proximity and similarities to Earth. To date, no proof of past or present life has been found on Mars. Cumulative evidence suggests that during the ancient Noachian time period, the surface environment of Mars had liquid water and may have been habitable for microorganisms, but habitable conditions do not necessarily indicate life.

<span class="mw-page-title-main">Martian spherules</span> Small iron oxide spherules found on Mars

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.

<span class="mw-page-title-main">Atmosphere of Mars</span> Layer of gases surrounding planet Mars

The atmosphere of Mars is the layer of gases surrounding Mars. It is primarily composed of carbon dioxide (95%), molecular nitrogen (2.85%), and argon (2%). It also contains trace levels of water vapor, oxygen, carbon monoxide, hydrogen, and noble gases. The atmosphere of Mars is much thinner than Earth's. The average surface pressure is only about 610 pascals (0.088 psi) which is less than 1% of the Earth's value.

<span class="mw-page-title-main">Scientific information from the Mars Exploration Rover mission</span>

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.

<span class="mw-page-title-main">Climate of Mars</span> Climate patterns of the terrestrial planet

The climate of Mars has been a topic of scientific curiosity for centuries, in part because it is the only terrestrial planet whose surface can be easily directly observed in detail from the Earth with help from a telescope.

<span class="mw-page-title-main">Aeolis quadrangle</span> One of a series of 30 quadrangle maps of Mars

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.

<span class="mw-page-title-main">Water on Mars</span> Study of past and present water on Mars

Almost all water on Mars today exists as ice, though it also exists in small quantities as vapor in the atmosphere. What was thought to be low-volume liquid brines in shallow Martian soil, also called recurrent slope lineae, may be grains of flowing sand and dust slipping downhill to make dark streaks. While most water ice is buried, it is exposed at the surface across several locations on Mars. In the mid-latitudes, it is exposed by impact craters, steep scarps and gullies. Additionally, water ice is also visible at the surface at the north polar ice cap. Abundant water ice is also present beneath the permanent carbon dioxide ice cap at the Martian south pole. More than 5 million km3 of ice have been detected at or near the surface of Mars, enough to cover the whole planet to a depth of 35 meters (115 ft). Even more ice might be locked away in the deep subsurface.

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.

<span class="mw-page-title-main">Composition of Mars</span> Branch of the geology of Mars

The composition of Mars covers the branch of the geology of Mars that describes the make-up of the planet Mars.

<span class="mw-page-title-main">Aeolis Palus</span> Palus on Mars

Aeolis Palus is a plain between the northern wall of Gale crater and the northern foothills of Aeolis Mons on Mars. It is located at 4.47°S 137.42°E.

<span class="mw-page-title-main">Sample Analysis at Mars</span>

Sample Analysis at Mars (SAM) is a suite of instruments on the Mars Science Laboratory Curiosity rover. The SAM instrument suite will analyze organics and gases from both atmospheric and solid samples. It was developed by the NASA Goddard Space Flight Center, the Laboratoire des Atmosphères Milieux Observations Spatiales (LATMOS) associated to the Laboratoire Inter-Universitaire des Systèmes Atmosphériques (LISA), and Honeybee Robotics, along with many additional external partners.

<span class="mw-page-title-main">Timeline of Mars Science Laboratory</span> Event timeline of the NASA Mars Science Laboratory mission

The Mars Science Laboratory and its rover, Curiosity, were launched from Earth on November 26, 2011. As of March 1, 2024, Curiosity has been on the planet Mars for 4112 sols since landing on August 6, 2012. (See Current status.)

<span class="mw-page-title-main">CheMin</span>

CheMin, short for Chemistry and Mineralogy, is an instrument located in the interior of the Curiosity rover that is exploring the surface of Gale crater on Mars. David Blake, from NASA Ames Research Center, is the Principal Investigator.

<span class="mw-page-title-main">Rocknest (Mars)</span> Sandpatch

Rocknest is a sand patch on the surface of Aeolis Palus, between Peace Vallis and Aeolis Mons, in Gale crater on the planet Mars. The patch was encountered by the Curiosity rover on the way from Bradbury Landing to Glenelg Intrigue on September 28, 2012. The approximate site coordinates are: 4.59°S 137.44°E.

<span class="mw-page-title-main">Icebreaker Life</span>

Icebreaker Life is a Mars lander mission concept proposed to NASA's Discovery Program. The mission involves a stationary lander that would be a near copy of the successful 2008 Phoenix and InSight spacecraft, but would carry an astrobiology scientific payload, including a drill to sample ice-cemented ground in the northern plains to conduct a search for biosignatures of current or past life on Mars.

<span class="mw-page-title-main">Martian regolith simulant</span>

Martian regolith 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 regolith such as dust mitigation of transportation equipment, advanced life support systems and in-situ resource utilization.

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.

References

  1. 1 2 Certini, Giacomo; Ugolini, Fiorenzo C. (2013). "An updated, expanded, universal definition of soil". Geoderma. 192: 378–379. Bibcode:2013Geode.192..378C. doi:10.1016/j.geoderma.2012.07.008.
  2. 1 2 3 Karunatillake, Suniti; Keller, John M.; Squyres, Steven W.; Boynton, William V.; Brückner, Johannes; Janes, Daniel M.; Gasnault, Olivier; Newsom, Horton E. (2007). "Chemical compositions at Mars landing sites subject to Mars Odyssey Gamma Ray Spectrometer constraints". Journal of Geophysical Research. 112 (E8): E08S90. Bibcode:2007JGRE..112.8S90K. doi: 10.1029/2006JE002859 .
  3. ↑ June 2013, Leonard David 13 (June 13, 2013). "Toxic Mars: Astronauts Must Deal with Perchlorate on the Red Planet". Space.com. Retrieved April 28, 2021.{{cite web}}: CS1 maint: numeric names: authors list (link)
  4. 1 2 "Toxic Mars: Astronauts Must Deal with Perchlorate on the Red Planet". space.com. June 13, 2013. Retrieved November 26, 2018.
  5. ↑ He, H; Gao, H; Chen, G; Li, H; Lin, H; Shu, Z (May 15, 2013). "Effects of perchlorate on growth of four wetland plants and its accumulation in plant tissues". Environmental Science and Pollution Research International. 20 (10): 7301–8. doi:10.1007/s11356-013-1744-4. PMID   23673920. S2CID   21398332.
  6. ↑ Heinz, Jacob; Waajen, Annemiek C.; Airo, Alessandro; Alibrandi, Armando; Schirmack, Janosch; Schulze-Makuch, Dirk (November 1, 2019). "Bacterial Growth in Chloride and Perchlorate Brines: Halotolerances and Salt Stress Responses of Planococcus halocryophilus". Astrobiology. 19 (11): 1377–1387. Bibcode:2019AsBio..19.1377H. doi:10.1089/ast.2019.2069. ISSN   1531-1074. PMC   6818489 . PMID   31386567.
  7. ↑ Heinz, Jacob; Krahn, Tim; Schulze-Makuch, Dirk (April 28, 2020). "A New Record for Microbial Perchlorate Tolerance: Fungal Growth in NaClO4 Brines and its Implications for Putative Life on Mars". Life. 10 (5): 53. Bibcode:2020Life...10...53H. doi: 10.3390/life10050053 . ISSN   2075-1729. PMC   7281446 . PMID   32353964.
  8. ↑ Heinz, Jacob; Doellinger, Joerg; Maus, Deborah; Schneider, Andy; Lasch, Peter; Grossart, Hans‐Peter; Schulze‐Makuch, Dirk (August 10, 2022). "Perchlorate‐specific proteomic stress responses of Debaryomyces hansenii could enable microbial survival in Martian brines". Environmental Microbiology. 24 (11): 1462–2920.16152. doi: 10.1111/1462-2920.16152 . ISSN   1462-2912. PMID   35920032.
  9. ↑ Logan, Bruce E; Wu, Jun; Unz, Richard F (August 1, 2001). "Biological Perchlorate Reduction in High-Salinity Solutions". Water Research. 35 (12): 3034–3038. Bibcode:2001WatRe..35.3034L. doi:10.1016/S0043-1354(01)00013-6. ISSN   0043-1354. PMID   11471705.
  10. ↑ "Mars covered in toxic chemicals that can wipe out living organisms, tests reveal". The Guardian. July 6, 2017. Retrieved November 26, 2018.
  11. ↑ Hecht, Jeff (March 9, 2007). "Martian dust may be hazardous to your health". New Scientist. 225 (Earth & Planetary Sciences Letters): 41. Retrieved November 30, 2018.
  12. ↑ "MEPAG Goal 5: Toxic Effects of Martian Dust on Humans". Mars Exploration Program Analysis Group. NASA Jet Propulsion Laboratory. Retrieved November 30, 2018.
  13. ↑ Webster, Guy (July 31, 2014). "Mars 2020 Rover's PIXL to Focus X-Rays on Tiny Targets". NASA . Retrieved July 31, 2014.
  14. ↑ "Adaptive sampling for rover x-ray lithochemistry" (PDF). Archived from the original (PDF) on 8 August 2014.
  15. ↑ Webster, Guy (July 31, 2014). "SHERLOC to Micro-Map Mars Minerals and Carbon Rings". NASA . Retrieved July 31, 2014.
  16. ↑ "SHERLOC: Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals, an Investigation for 2020" (PDF).
  17. 1 2 Brown, Dwayne; Webster, Guy; Neal-Jones, Nancy (December 3, 2012). "NASA Mars Rover Fully Analyzes First Martian Soil Samples". NASA . Archived from the original on December 5, 2012. Retrieved December 3, 2012.
  18. 1 2 Chang, Ken (December 3, 2012). "Mars Rover Discovery Revealed". New York Times . Retrieved December 3, 2012.
  19. ↑ Yen, A.S.; Kim, S.S.; Hecht, M.H.; Frant, M.S.; Murray, B. (2000). "Evidence that the reactivity of the Martian soil is due to superoxide ions". Science. 289 (5486): 1909–12. Bibcode:2000Sci...289.1909Y. doi:10.1126/science.289.5486.1909. PMID   10988066.
  20. 1 2 Brown, Dwayne (October 30, 2012). "NASA Rover's First Soil Studies Help Fingerprint Martian Minerals". NASA . Retrieved October 31, 2012.
  21. ↑ Chinnery, H.E.; Hagermann, A.; Kaufmann, E.; Lewis, S.R. (February 2019). "The Penetration of Solar Radiation Into Water and Carbon Dioxide Snow, With Reference to Mars". Journal of Geophysical Research: Planets. 124 (2): 337–348. Bibcode:2019JGRE..124..337C. doi: 10.1029/2018JE005771 . hdl: 1893/28687 . S2CID   85509108.
  22. ↑ Mitrofanov, I. et 11 al.; Anfimov; Kozyrev; Litvak; Sanin; Tret'Yakov; Krylov; Shvetsov; Boynton; Shinohara; Hamara; Saunders (2004). "Mineralogy at Gusev crater from the Mössbauer spectrometer on the Spirit rover". Science. 297 (5578): 78–81. Bibcode:2002Sci...297...78M. doi: 10.1126/science.1073616 . PMID   12040089. S2CID   589477.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  23. ↑ Horneck, G. (2008). "The microbial case for Mars and its implications for human expeditions to Mars". Acta Astronautica. 63 (7–10): 1015–1024. Bibcode:2008AcAau..63.1015H. doi:10.1016/j.actaastro.2007.12.002.
  24. ↑ Morris, R.V. et 16 al.; Klingelhöfer; Bernhardt; Schröder; Rodionov; De Souza; Yen; Gellert; Evlanov; Foh; Kankeleit; Gütlich; Ming; Renz; Wdowiak; Squyres; Arvidson (2004). "Mineralogy at Gusev crater from the Mössbauer spectrometer on the Spirit rover". Science. 305 (5685): 833–6. Bibcode:2004Sci...305..833M. doi:10.1126/science.1100020. PMID   15297666. S2CID   8072539.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  25. ↑ "Martian soil 'could support life'". BBC News. June 27, 2008. Retrieved August 7, 2008.
  26. ↑ Chang, Alicia (August 5, 2008). "Scientists: Salt in Mars soil not bad for life". USA Today. Associated Press. Retrieved August 7, 2008.
  27. ↑ "NASA Spacecraft Analyzing Martian Soil Data". JPL. Archived from the original on May 22, 2017. Retrieved August 5, 2008.
  28. ↑ "Measuring Electrostatic Phenomena on Mars and the Moon" (PDF). Proceedings of The Institute of Electrostatics Japan Annual Meeting, Tokyo, Japan, September 2001. Retrieved October 5, 2021.
  29. ↑ Certini, G; Scalenghe, R; Amundson, R (2009). "A view of extraterrestrial soils". European Journal of Soil Science. 60 (6): 1078–1092. doi:10.1111/j.1365-2389.2009.01173.x. S2CID   130736656.
  30. ↑ L. W. Beegle; G. H. Peters; G. S. Mungas; G. H. Bearman; J. A. Smith; R. C. Anderson (2007). Mojave Martian Simulant: A New Martian Soil Simulant (PDF). Lunar and Planetary Science XXXVIII. Retrieved April 28, 2014.
  31. ↑ Satherley, Dan (December 4, 2012). "'Complex chemistry' found on Mars". 3 News . Archived from the original on March 9, 2014. Retrieved December 4, 2012.
  32. ↑ Lieberman, Josh (September 26, 2013). "Mars Water Found: Curiosity Rover Uncovers 'Abundant, Easily Accessible' Water In Martian Soil". iSciencetimes. Retrieved September 26, 2013.
  33. ↑ Leshin, L. A.; Cabane, M.; Coll, P.; Conrad, P. G.; Archer, P. D.; Atreya, S. K.; Brunner, A. E.; Buch, A.; Eigenbrode, J. L.; Flesch, G. J.; Franz, H. B.; Freissinet, C.; Glavin, D. P.; McAdam, A. C.; Miller, K. E.; Ming, D. W.; Morris, R. V.; Navarro-Gonzalez, R.; Niles, P. B.; Owen, T.; Pepin, R. O.; Squyres, S.; Steele, A.; Stern, J. C.; Summons, R. E.; Sumner, D. Y.; Sutter, B.; Szopa, C. (September 27, 2013). "Volatile, Isotope, and Organic Analysis of Martian Fines with the Mars Curiosity Rover". Science . 341 (6153): 1238937. Bibcode:2013Sci...341E...3L. doi:10.1126/science.1238937. PMID   24072926. S2CID   206549244.
  34. 1 2 Grotzinger, John (September 26, 2013). "Introduction To Special Issue: Analysis of Surface Materials by the Curiosity Mars Rover". Science . 341 (6153): 1475. Bibcode:2013Sci...341.1475G. doi: 10.1126/science.1244258 . PMID   24072916.
  35. ↑ Neal-Jones, Nancy; Zubritsky, Elizabeth; Webster, Guy; Martialay, Mary (September 26, 2013). "Curiosity's SAM Instrument Finds Water and More in Surface Sample". NASA . Retrieved September 27, 2013.
  36. 1 2 Webster, Guy; Brown, Dwayne (September 26, 2013). "Science Gains From Diverse Landing Area of Curiosity". NASA . Retrieved September 27, 2013.
  37. 1 2 Chang, Kenneth (October 1, 2013). "Hitting Pay Dirt on Mars". New York Times . Retrieved October 2, 2013.
  38. 1 2 Meslin, P.-Y.; Forni, O.; Schroder, S.; Cousin, A.; Berger, G.; Clegg, S. M.; Lasue, J.; Maurice, S.; Sautter, V.; Le Mouelic, S.; Wiens, R. C.; Fabre, C.; Goetz, W.; Bish, D.; Mangold, N.; Ehlmann, B.; Lanza, N.; Harri, A.- M.; Anderson, R.; Rampe, E.; McConnochie, T. H.; Pinet, P.; Blaney, D.; Leveille, R.; Archer, D.; Barraclough, B.; Bender, S.; Blake, D.; Blank, J. G.; et al. (September 26, 2013). "Soil Diversity and Hydration as Observed by ChemCam at Gale Crater, Mars". Science . 341 (6153): 1238670. Bibcode:2013Sci...341E...1M. CiteSeerX   10.1.1.397.5426 . doi:10.1126/science.1238670. PMID   24072924. S2CID   7418294 . Retrieved September 27, 2013.
  39. ↑ Stolper, E.M.; Baker, M.B.; Newcombe, M.E.; Schmidt, M.E.; Treiman, A.H.; Cousin, A.; Dyar, M.D.; Fisk, M.R.; Gellert, R.; King, P.L.; Leshin, L.; Maurice, S.; McLennan, S.M.; Minitti, M.E.; Perrett, G.; Rowland, S.; Sautter, V.; Wiens, R.C.; MSL ScienceTeam, O.; Bridges, N.; Johnson, J. R.; Cremers, D.; Bell, J. F.; Edgar, L.; Farmer, J.; Godber, A.; Wadhwa, M.; Wellington, D.; McEwan, I.; et al. (2013). "The Petrochemistry of Jake_M: A Martian Mugearite" (PDF). Science . 341 (6153): 1239463. Bibcode:2013Sci...341E...4S. doi:10.1126/science.1239463. PMID   24072927. S2CID   16515295.
  40. ↑ Good, Andrew (April 11, 2019). "Curiosity Tastes First Sample in 'Clay-Bearing Unit'". NASA . Retrieved April 12, 2019.
  41. ↑ Certini, Giacomo; Karunatillake, Suniti; Zhao, Yu-Yan Sara; Meslin, Pierre-Yves; Cousin, Agnes; Hood, Donald R.; Scalenghe, Riccardo (2020). "Disambiguating the soils of Mars". Earth & Planetary and Space Science. 186: 104922. Bibcode:2020P&SS..18604922C. doi:10.1016/j.pss.2020.104922. hdl: 10447/408671 . S2CID   216509538.
  42. 1 2 Cantor, B (2007). "MOC observations of the 2001 Mars planet-encircling dust storm". Icarus . 186 (1): 60–96. Bibcode:2007Icar..186...60C. doi:10.1016/j.icarus.2006.08.019.
  43. 1 2 Claudin, P; Andreotti, B (2006). "A scaling law for aeolian dunes on Mars, Venus, Earth, and for subaqueous ripples". Earth and Planetary Science Letters . 252 (1–2): 30–44. arXiv: cond-mat/0603656 . Bibcode:2006E&PSL.252...30C. doi:10.1016/j.epsl.2006.09.004. S2CID   13910286.
  44. ↑ Sullivan, R.; Arvidson, R.; Bell, J. F.; Gellert, R.; Golombek, M.; Greeley, R.; Herkenhoff, K.; Johnson, J.; Thompson, S.; Whelley, P.; Wray, J. (2008). "Wind-driven particle mobility on Mars: Insights from Mars Exploration Rover observations at "El Dorado" and surroundings at Gusev Crater". Journal of Geophysical Research . 113 (E6): E06S07. Bibcode:2008JGRE..113.6S07S. doi: 10.1029/2008JE003101 .
  45. ↑ Hamilton, Victoria E.; McSween, Harry Y.; Hapke, Bruce (2005). "Mineralogy of Martian atmospheric dust inferred from thermal infrared spectra of aerosols". Journal of Geophysical Research. 110 (E12): E12006. Bibcode:2005JGRE..11012006H. CiteSeerX   10.1.1.579.2798 . doi:10.1029/2005JE002501.
  46. ↑ Goetz et al. (2007), Seventh Mars Conference
  47. ↑ Goetz, W; Bertelsen, P; Binau, Cs; Gunnlaugsson, Hp; Hviid, Sf; Kinch, Km; Madsen, De; Madsen, Mb; Olsen, M; Gellert, R; Klingelhöfer, G; Ming, Dw; Morris, Rv; Rieder, R; Rodionov, Ds; De Souza, Pa Jr; Schröder, C; Squyres, Sw; Wdowiak, T; Yen, A (July 2005). "Indication of drier periods on Mars from the chemistry and mineralogy of atmospheric dust". Nature. 436 (7047): 62–5. Bibcode:2005Natur.436...62G. doi:10.1038/nature03807. ISSN   0028-0836. PMID   16001062. S2CID   10341702.
  48. ↑ Edgett, Kenneth S. (2002). "Low-albedo surfaces and eolian sediment: Mars Orbiter Camera views of western Arabia Terra craters and wind streaks". Journal of Geophysical Research. 107 (E6): 5038. Bibcode:2002JGRE..107.5038E. doi:10.1029/2001JE001587. hdl: 2060/20010069272 .
  49. ↑ Lemmon, Mt; Wolff, Mj; Smith, Md; Clancy, Rt; Banfield, D; Landis, Ga; Ghosh, A; Smith, Ph; Spanovich, N; Whitney, B; Whelley, P; Greeley, R; Thompson, S; Bell, Jf 3Rd; Squyres, Sw (December 2004). "Atmospheric imaging results from the Mars exploration rovers: Spirit and Opportunity". Science. 306 (5702): 1753–6. Bibcode:2004Sci...306.1753L. doi:10.1126/science.1104474. ISSN   0036-8075. PMID   15576613. S2CID   5645412.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  50. ↑ Ojha, Lujendra; Lewis, Kevin; Karunatillake, Suniti; Schmidt, Mariek (July 20, 2018). "The Medusae Fossae Formation as the single largest source of dust on Mars". Nature Communications . 9 (2867 (2018)): 2867. Bibcode:2018NatCo...9.2867O. doi: 10.1038/s41467-018-05291-5 . PMC   6054634 . PMID   30030425.
  51. ↑ "Lunar & Mars Soil Simulant". Orbitec. Retrieved April 27, 2014.
  52. ↑ Lab, Exolith. "MGS-1 Mars Global Simulant | Fact Sheet" (PDF). Exolith Simulants.
  53. ↑ "NASA Captures Mars' Mesmerizing Blue Sand Dune — but What Caused It?". June 25, 2018.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.