
The Lunae Palus quadrangle is one of a series of
30 quadrangle maps of Mars used by the
United States Geological Survey
The United States Geological Survey (USGS), founded as the Geological Survey, is an agency of the U.S. Department of the Interior whose work spans the disciplines of biology, geography, geology, and hydrology. The agency was founded on Mar ...
(USGS)
Astrogeology Research Program
The Astrogeology Science Center is the entity within the United States Geological Survey concerned with the study of planetary geology and planetary cartography. It is housed in the Shoemaker Building in Flagstaff, Arizona. The Center was esta ...
. The
quadrangle is also referred to as MC-10 (Mars Chart-10). Lunae Planum and parts of
Xanthe Terra and
Chryse Planitia
Chryse Planitia (Greek, "''Golden Plain''") is a smooth circular plain in the northern equatorial region of Mars close to the Tharsis region to the west, centered at . Chryse Planitia lies partially in the Lunae Palus quadrangle, partially in t ...
are found in the Lunae Palus quadrangle. The Lunae Palus quadrangle contains many ancient river valleys.
The quadrangle covers the area from 45° to 90° west longitude and 0° to 30° north latitude on
Mars
Mars is the fourth planet from the Sun. It is also known as the "Red Planet", because of its orange-red appearance. Mars is a desert-like rocky planet with a tenuous carbon dioxide () atmosphere. At the average surface level the atmosph ...
. The ''
Viking 1
''Viking 1'' was the first of two spacecraft, along with '' Viking 2'', each consisting of an orbiter and a lander, sent to Mars as part of NASA's Viking program. The lander touched down on Mars on July 20, 1976, the first successful Mars lan ...
'' Lander (part of
Viking program
The ''Viking'' program consisted of a pair of identical American space probes, ''Viking 1'' and ''Viking 2'' both launched in 1975, and landed on Mars in 1976. The mission effort began in 1968 and was managed by the NASA Langley Research Cent ...
) landed in the quadrangle on July 20, 1976, at . It was the first robot spacecraft to successfully land on the Red Planet.
Results from ''Viking I'' mission
What would it look like walking around the landing site
The sky would be a light pink. The dirt would also appear pink.
Rocks of many sizes would be spread about. One large rock, named Big Joe, is as big as a banquet table. Some boulders would show erosion due to the wind. There would be many small sand dunes that are still active. The wind speed would typically be 7 meters per second (16 miles per hour). There would be a hard crust on the top of the soil similar to a deposit, called caliche which is common in the U.S. Southwest. Such crusts are formed by solutions of minerals moving up through soil and evaporating at the surface.
Analysis of soil

The soil resembled those produced from the weathering of basaltic
lava
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a Natural satellite, moon onto its surface. Lava may be erupted at a volcano or through a Fissure vent, fractu ...
s. The tested soil contained abundant
silicon
Silicon is a chemical element; it has symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic lustre, and is a tetravalent metalloid (sometimes considered a non-metal) and semiconductor. It is a membe ...
and
iron
Iron is a chemical element; it has symbol Fe () and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, forming much of Earth's o ...
, along with significant amounts of
magnesium
Magnesium is a chemical element; it has Symbol (chemistry), 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 ...
,
aluminum
Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...
,
sulfur
Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms ...
,
calcium
Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to it ...
, and
titanium
Titanium is a chemical element; it has symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resistant to corrosion in ...
. Trace elements,
strontium
Strontium is a chemical element; it has symbol Sr and atomic number 38. An alkaline earth metal, it is a soft silver-white yellowish metallic element that is highly chemically reactive. The metal forms a dark oxide layer when it is exposed to ...
and
yttrium
Yttrium is a chemical element; it has Symbol (chemistry), symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanides and has often been classified as a "rare-earth element". Yttrium is almost a ...
, were detected. The amount of
potassium
Potassium is a chemical element; it has Symbol (chemistry), symbol K (from Neo-Latin ) and atomic number19. It is a silvery white metal that is soft enough to easily cut with a knife. Potassium metal reacts rapidly with atmospheric oxygen to ...
was five times lower than the average for the Earth's crust. Some chemicals in the soil contained sulfur and
chlorine
Chlorine is a chemical element; it has Symbol (chemistry), 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 ...
that were like those remaining after the evaporation of sea water. Sulfur was more concentrated in the crust on top of the soil than in the bulk soil beneath. The sulfur may be present as
sulfates
The sulfate or sulphate ion is a Polyatomic ion, polyatomic anion with the empirical formula . Salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life. Sulfates are salt (chemistry), ...
of
sodium
Sodium is a chemical element; it has Symbol (chemistry), symbol Na (from Neo-Latin ) and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 element, group 1 of the peri ...
, magnesium, calcium, or iron. A
sulfide
Sulfide (also sulphide in British English) is an inorganic anion of sulfur with the chemical formula S2− or a compound containing one or more S2− ions. Solutions of sulfide salts are corrosive. ''Sulfide'' also refers to large families o ...
of iron is also possible. Both the
''Spirit'' rover and the
''Opportunity'' rover also found sulfates on Mars; consequently sulfates may be common on the Martian surface. The ''Opportunity'' rover (landed in 2004 with advanced instruments) found magnesium sulfate and calcium sulfate at
Meridiani Planum
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 bound water. The iron oxide in the spherules is crystalline (grey) hematite (Fe ...
. Using results from the chemical measurements, mineral models suggest that the soil could be a mixture of about 80% iron-rich
clay
Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolinite, ). Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impuriti ...
, about 10%
magnesium sulfate
Magnesium sulfate or magnesium sulphate is a chemical compound, a salt with the formula , consisting of magnesium cations (20.19% by mass) and sulfate anions . It is a white crystalline solid, soluble in water but not in ethanol.
Magnesi ...
(
kieserite
Kieserite, or magnesium sulfate monohydrate, is a hydrous magnesium sulfate mineral with formula (MgSO4·H2O).
It has a vitreous luster and it is colorless, grayish-white or yellowish. Its hardness is 3.5 and crystallizes in the monoclinic crys ...
?), about 5%
carbonate
A carbonate is a salt of carbonic acid, (), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word "carbonate" may also refer to a carbonate ester, an organic compound containing the carbonate group ...
(
calcite
Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on ...
), and about 5%
iron oxides
An iron oxide is a chemical compound composed of iron and oxygen. Several iron oxides are recognized. Often they are nonstoichiometric, non-stoichiometric. Ferric oxyhydroxides are a related class of compounds, perhaps the best known of which is ...
(
hematite
Hematite (), also spelled as haematite, is a common iron oxide compound with the formula, Fe2O3 and is widely found in rocks and soils. Hematite crystals belong to the rhombohedral lattice system which is designated the alpha polymorph of . ...
,
magnetite
Magnetite is a mineral and one of the main iron ores, with the chemical formula . It is one of the iron oxide, oxides of iron, and is ferrimagnetism, ferrimagnetic; it is attracted to a magnet and can be magnetization, magnetized to become a ...
,
goethite
Goethite (, ) is a mineral of the diaspore group, consisting of iron(III) oxide-hydroxide, specifically the α- polymorph. It is found in soil and other low-temperature environments such as sediment. Goethite has been well known since ancient t ...
?). These minerals are typical weathering products of mafic
igneous rocks
Igneous rock ( ), or magmatic rock, is one of the three main Rock (geology)#Classification, rock types, the others being sedimentary rock, sedimentary and metamorphic rock, metamorphic. Igneous rocks are formed through the cooling and solidifi ...
. Studies with
magnets
A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, steel, nickel, ...
aboard the landers indicated that the soil is 3–7% magnetic materials by weight. The magnetic chemicals could be
magnetite
Magnetite is a mineral and one of the main iron ores, with the chemical formula . It is one of the iron oxide, oxides of iron, and is ferrimagnetism, ferrimagnetic; it is attracted to a magnet and can be magnetization, magnetized to become a ...
and
maghemite
Maghemite (Fe2O3, γ-Fe2O3) is a member of the family of iron oxides. It has the same formula as hematite, but the same spinel ferrite structure as magnetite () and is also ferrimagnetic. It is sometimes spelled as "maghaemite".
''Maghemite'' ...
. These could come from the weathering of
basalt
Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...
rock. Experiments carried out by the Mars ''Spirit'' rover (landed in 2004) indicated that magnetite could explain the magnetic nature of the dust and soil on Mars. Magnetite was found in the soil and that the most magnetic part of the soil was dark. Magnetite is very dark.
Search for life
Viking did three experiments looking for life. The results were surprising and interesting. Most scientists now believe that the data were due to inorganic chemical reactions of the soil. But a few still believe the results were due to living reactions. No organic chemicals were found in the soil; hence nearly all the scientific community thought that no life was found because no organic chemicals were detected. Not finding any organics was unusual since
meteorites
A meteorite is a rock that originated in outer space and has fallen to the surface of a planet or moon. When the original object enters the atmosphere, various factors such as friction, pressure, and chemical interactions with the atmospheri ...
raining on Mars for 5 billion years or so would surely bring some organics. Moreover, dry areas of
Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. ...
do not have detectable organic compounds either, but they have organisms living in the rocks. Mars has almost no ozone layer, unlike the Earth, so UV light sterilizes the surface and produces highly reactive chemicals such as peroxides that would oxidize any organic chemicals. Perchlorate may be the oxidizing chemical. The
''Phoenix'' lander discovered the chemical
perchlorate
A perchlorate is a chemical compound containing the perchlorate ion, , the conjugate base of perchloric acid (ionic perchlorate). As counterions, there can be metal cations, quaternary ammonium cations or other ions, for example, nitronium cat ...
in the Martian Soil. Perchlorate is a strong oxidant so it may have destroyed any organic matter on the surface. If it is widespread on Mars, carbon-based life would be difficult at the soil surface.
The question of life on Mars received a new, important twist when research, published in the ''Journal of Geophysical Research'' in September 2010, proposed that organic compounds were actually present in the soil analyzed by both ''Viking 1'' and ''2''. NASA's ''Phoenix'' lander in 2008 detected perchlorate which can break down organic compounds. The study's authors found that perchlorate will destroy organics when heated and will produce
chloromethane
Chloromethane, also called methyl chloride, Refrigerant-40, R-40 or HCC 40, is an organic compound with the chemical formula . One of the haloalkanes, it is a colorless, sweet-smelling, flammable gas. Methyl chloride is a crucial reagent in indu ...
and
dichloromethane
Dichloromethane (DCM, methylene chloride, or methylene bichloride) is an organochlorine compound with the formula . This colorless, volatile liquid with a chloroform-like, sweet odor is widely used as a solvent. Although it is not miscible with ...
, the identical chlorine compounds discovered by both Viking landers when they performed the same tests on Mars. Because perchlorate would have broken down any Martian organics, the question of whether or not Viking found life is still wide open.
Mars Science Laboratory
Hypanis Vallis
The Hypanis Valles are a set of channels in a 270 km valley in Xanthe Terra on Mars at 11° N, 314° E, in the Lunae Palus quadrangle. They appear to have been carved by long-lived flowing water, and a significant deposit (interpreted by so ...
, in the Lunae Palus quadrangle, was one of the sites proposed as a landing site for the
Mars Science Laboratory
Mars Science Laboratory (MSL) is a robotic spacecraft, robotic space probe mission to Mars launched by NASA on November 26, 2011, which successfully landed ''Curiosity (rover), Curiosity'', a Mars rover, in Gale (crater), Gale Crater on Augus ...
, popularly known as the Mars
''Curiosity'' rover. One aim of the Mars Science Laboratory is to search for signs of ancient life, as many Martian rocks occur in a context of
hydrogeology
Hydrogeology (''hydro-'' meaning water, and ''-geology'' meaning the study of the Earth) is the area of geology that deals with the distribution and movement of groundwater in the soil and rock (geology), rocks of the Earth's crust (ge ...
, that is, they were formed in water, at the bottom of lakes or seas, or by water percolating through the soil, although Brown University researchers have recently suggested outgassing of steam to atmosphere from a new planet's interior can also produce the clay minerals seen in these rocks.
Because such issues remain unresolved, it is hoped that a later mission could return samples from sites identified as offering best chances for remains of life. To bring the craft down safely, a 12-mile wide, smooth, flat circle was needed. Geologists hoped to examine places where water once ponded, and to examine its sediment layers. The site eventually settled on for the Mars Science Laboratory was
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 a ...
in the
Aeolis quadrangle
The Aeolis quadrangle is one of a series of list of quadrangles on Mars, 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 (Mars Chart-2 ...
, and a successful landing took place there in 2012. The rover is still operational as of early 2019. NASA scientists believe Gale Crater's floor rocks are indeed sedimentary, formed in pooled water.
Kasei Valles

One of the most significant features of the Lunae Palus region, Kasei Valles, is one of the largest outflow channels on Mars. Like other outflow channels, it was carved by liquid water, probably during gigantic floods.
Kasei is about long. Some sections of Kasei Valles are wide. It begins in
Echus Chasma
Echus Chasma is a chasma in the Lunae Planum high plateau north of the Valles Marineris canyon system of Mars. It is in the Coprates quadrangle.ESA (2008-07-14). Echus Chasma. Retrieved on 2008-07-15 from http://www.esa.int/esaSC/SEM4CATHKHF_i ...
, near
Valles Marineris
Valles Marineris (; Latin for ''Mariner program, Mariner Valleys'', named after the Mariner 9 Mars orbiter of 1971–72 which discovered it) is a system of canyons that runs along the Mars, Martian surface east of the Tharsis region. At more than ...
, and empties into
Chryse Planitia
Chryse Planitia (Greek, "''Golden Plain''") is a smooth circular plain in the northern equatorial region of Mars close to the Tharsis region to the west, centered at . Chryse Planitia lies partially in the Lunae Palus quadrangle, partially in t ...
, not far from where
Viking 1
''Viking 1'' was the first of two spacecraft, along with '' Viking 2'', each consisting of an orbiter and a lander, sent to Mars as part of NASA's Viking program. The lander touched down on Mars on July 20, 1976, the first successful Mars lan ...
landed. Sacra Mensa, a large tableland, divides Kasei into northern and southern channels. It is one of the longest continuous outflow channels on Mars. At around 20° north latitude Kasei Valles splits into two channels, called Kasei Vallis Canyon and North Kasei Channel. These branches recombine at around 63° west longitude. Some parts of Kasei Valles are 2–3 km deep.
Scientists suggest it was formed several episodes of flooding and maybe by some glacial activity.
Craters

Impact craters generally have a rim with ejecta around them, in contrast volcanic craters usually do not have a rim or ejecta deposits. As craters get larger (greater than 10 km in diameter) they usually have a central peak. The peak is caused by a rebound of the crater floor following the impact.
Sometimes craters will display layers. Craters can show us what lies deep under the surface.
Fossa
Large troughs (long narrow depressions) are called fossae in the geographical language used for Mars. This term is derived from Latin; therefore fossa is singular and fossae is plural. Troughs form when the crust is stretched until it breaks. The stretching can be due to the large weight of a nearby volcano. Fossae/pit craters are common near volcanoes in the Tharsis and Elysium system of volcanoes.
[Skinner, J., L. Skinner, and J. Kargel. 2007. Re-assessment of Hydrovolcanism-based Resurfacing within the Galaxias Fossae Region of Mars. Lunar and Planetary Science XXXVIII (2007)]
See also
*
Chaos terrain
In astrogeology, chaos terrain, or chaotic terrain, is a planetary surface area where features such as ridges, cracks, and plains appear jumbled and enmeshed with one another. Chaos terrain is a notable feature of the planets Mars and Mercury, ...
*
Climate of Mars
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 Earth with help from a telescope.
Although Mars is small ...
*
Fossa (geology)
In planetary nomenclature, a fossa (pl. fossae ) is a long, narrow depression (trough) on the surface of an extraterrestrial body, such as a planet or moon. The term, which means "ditch" or "trench" in Latin, is not a geological term as such ...
*
Geology of Mars
The geology of Mars is the scientific study of the surface, crust, and interior of the planet Mars. It emphasizes the composition, structure, history, and physical processes that shape the planet. It is analogous to the field of terrestrial geo ...
*
HiRISE
High Resolution Imaging Science Experiment is a camera on board the '' Mars Reconnaissance Orbiter'' which has been orbiting and studying Mars since 2006. The 65 kg (143 lb), US$40 million instrument was built under the direction ...
*
HiWish program
HiWish is a program created by NASA so that anyone can suggest a place for the HiRISE camera on the Mars Reconnaissance Orbiter to photograph. It was started in January 2010. In the first few months of the program 3000 people signed up to use HiR ...
*
Impact crater
An impact crater is a depression (geology), depression in the surface of a solid astronomical body formed by the hypervelocity impact event, impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal c ...
*
Lakes on Mars
In summer 1965, the first close-up images from Mars showed a cratered desert with no signs of water. However, over the decades, as more parts of the planet were imaged with better cameras on more sophisticated satellites, Mars showed evidence ...
*
List of areas of chaos terrain on Mars
*
List of rocks on Mars
Martian rocks and outcrops have been studied ''in-situ'' by various landers and rovers. While many of the rocks identified on the Martian surface are similar to each other, some have been considered scientifically important or otherwise notabl ...
*
Martian chaos terrain
*
River delta
A river delta is a landform, archetypically triangular, created by the deposition of the sediments that are carried by the waters of a river, where the river merges with a body of slow-moving water or with a body of stagnant water. The creat ...
*
Vallis Vallis (plural Valles) is Latin for valley, vale; it may refer to the following :
;Places and jurisdictions on Earth
* the Swiss canton Wallis
* Vallis (see), an ancient city, former bishopric and Latin Catholic titular see in Africa Proconsulari ...
*
Viking program
The ''Viking'' program consisted of a pair of identical American space probes, ''Viking 1'' and ''Viking 2'' both launched in 1975, and landed on Mars in 1976. The mission effort began in 1968 and was managed by the NASA Langley Research Cent ...
*
Water on Mars
Although very small amounts of liquid water may occur transiently on the surface of Mars, limited to traces of dissolved moisture from the atmosphere and thin films, large quantities of ice are present on and under the surface. Small amounts of ...
References
External links
{{Portal bar, Solar System
Mars