The Thermal Emission Spectrometer (TES) is an instrument on board

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 the a ...

. TES collects two types of data,

hyperspectral Hyperspectral imaging collects and processes information from across the electromagnetic spectrum. The goal of hyperspectral imaging is to obtain the spectrum for each pixel in the image of a scene, with the purpose of finding objects, identifyi ...

thermal infrared data from 6 to 50

micrometre The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...

s (μm) and bolometric visible-NIR (0.3 to 2.9 μm) measurements. TES has six detectors arranged in a 2x3 array, and each detector has a field of view of approximately 3 × 6 km on the surface of Mars. The TES instrument uses the natural harmonic vibrations of the chemical bonds in materials to determine the composition of gases, liquids, and solids. TES identified a large (30,000 square-kilometer) area that contained the mineral

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 ...

. Olivine was found in the

Nili Fossae Nili Fossae is a group of large, concentric grabens on Mars, in the Syrtis Major quadrangle. They have been eroded and partly filled in by sediments and clay-rich ejecta from a nearby giant impact crater, the Isidis basin. It is at approximatel ...

formation. It is thought that the ancient impact that created the

Isidis basin Isidis Planitia is a plain located within a giant impact basin on Mars, located partly in the Syrtis Major quadrangle and partly in the Amenthes quadrangle. At approximately in diameter, it is the third-largest obvious impact structure on the ...

resulted in faults that exposed the olivine. Olivine is present in many

mafic A mafic mineral or rock is a silicate mineral or igneous rock rich in magnesium and iron. Most mafic minerals are dark in color, and common rock-forming mafic minerals include olivine, pyroxene, amphibole, and biotite. Common mafic rocks include ...

volcanic

rock Rock most often refers to: * Rock (geology), a naturally occurring solid aggregate of minerals or mineraloids * Rock music, a genre of popular music Rock or Rocks may also refer to: Places United Kingdom * Rock, Caerphilly, a location in Wales ...

s. In the presence of water it weathers into minerals such as

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 ...

chlorite The chlorite ion, or chlorine dioxide anion, is the halite with the chemical formula of . A chlorite (compound) is a compound that contains this group, with chlorine in the oxidation state of +3. Chlorites are also known as salts of chlorous ac ...

smectite A smectite (from ancient Greek ''σμηκτός'' smektos 'lubricated'; ''σμηκτρίς'' smektris 'walker's earth', 'fuller's earth'; rubbing earth; earth that has the property of cleaning) is a mineral mixtures of various swelling sheet sil ...

maghemite Maghemite (Fe2O3, γ-Fe2O3) is a member of the family of iron oxides. It has the same spinel ferrite structure as magnetite and is also ferrimagnetic. It is sometimes spelled as "maghaemite". ''Maghemite'' can be considered as an Fe(II)-deficie ...

, and

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 . ...

. Olivine was also discovered in many other small outcrops within 60 degrees north and south of the equator. Olivine has also been found in the SNC (

shergottite A Martian meteorite is a rock that formed on Mars, was ejected from the planet by an impact event, and traversed interplanetary space before landing on Earth as a meteorite. , 277 meteorites had been classified as Martian, less than half a percen ...

nakhlite Nakhlites are a group of Martian meteorites, named after the first one, Nakhla meteorite. Nakhlites are igneous rocks that are rich in augite and were formed from basaltic magma about 1.3 billion years ago. They contain augite and olivine crysta ...

, and chassigny)

meteorites A meteorite is a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the atmosphere to reach the surface of a planet or moon. When the original object en ...

that are generally accepted to have come from Mars. Later studies have found the olivine-rich rocks to cover over 113,000 square kilometers. That is 11 times larger than the five volcanoes on the Big Island of Hawaii.
/ref>

References

* *{{cite journal , author=Bandfield J. L. , author2=Hamilton V. E. , author3=Christensen P. R. , title=A global view of Martian surface compositions from MGS-TES , journal=Science , volume=287 , issue=5458 , date=2000 , pages=1626–1630 , url=http://spot.fho-emden.de/nasa/mgs/sci/tes/TES_Science.pdf , archive-url=https://web.archive.org/web/20001006203029/http://spot.fho-emden.de/nasa/mgs/sci/tes/TES_Science.pdf , url-status=dead , archive-date=2000-10-06 , doi=10.1126/science.287.5458.1626 , bibcode=2000Sci...287.1626B Spectrometers Spacecraft instruments Mars Global Surveyor

See also

References