Columbus is a crater in the
Terra Sirenum
Terra Sirenum is a large region in the southern hemisphere of the planet Mars. It is centered at and covers 3900 km at its broadest extent. It covers latitudes 10 to 70 South and longitudes 110 to 180 W. Terra Sirenum is an upland area nota ...
of Mars. It is 119 km in diameter and was named after
Christopher Columbus
Christopher Columbus
* lij, Cristoffa C(or)ombo
* es, link=no, Cristóbal Colón
* pt, Cristóvão Colombo
* ca, Cristòfor (or )
* la, Christophorus Columbus. (; born between 25 August and 31 October 1451, died 20 May 1506) was a ...
, Italian explorer (1451–1506). The discovery of sulfates and clay minerals in sediments within Columbus crater are strong evidence that a lake once existed in the crater. Research with an orbiting near-infrared
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 ...
, which reveals the types of minerals present based on the wavelengths of light they absorb, found evidence of layers of both clay and sulfates in Columbus crater. This is exactly what would appear if a large lake had slowly evaporated. Moreover, because some layers contained
gypsum
Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard or sidewalk chalk, and drywall. ...
, a sulfate which forms in relatively fresh water, life could have formed in the crater.
52438cameramap.jpg, Map showing the relative positions of Columbus crater and other nearby craters in Memnonia quadrangle
The Memnonia quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Memnonia quadrangle is also referred to as MC-16 (Mars Chart-16).
The quadrangle is ...
Layers
Columbus crater contains layers, also called strata. In Columbus crater, the CRISM instrument on the
Mars Reconnaissance Orbiter
''Mars Reconnaissance Orbiter'' (MRO) is a spacecraft designed to study the geology and climate of Mars, provide reconnaissance of future landing sites, and relay data from surface missions back to Earth. It was launched on August 12, 2005, an ...
found
kaolinite
Kaolinite ( ) is a clay mineral, with the chemical composition Al2 Si2 O5( OH)4. It is an important industrial mineral. It is a layered silicate mineral, with one tetrahedral sheet of silica () linked through oxygen atoms to one octahedral ...
, hydrated sulfates including
alunite and possibly
jarosite
Jarosite is a basic hydrous sulfate of potassium and ferric iron (Fe-III) with a chemical formula of KFe3(SO4)2(OH)6. This sulfate mineral is formed in ore deposits by the oxidation of iron sulfides. Jarosite is often produced as a byproduct du ...
. Further study concluded that
gypsum
Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard or sidewalk chalk, and drywall. ...
, polyhydrated and monohydrated Mg/Fe-sulfates were common and small deposits of montmorillonite, Fe/Mg-phyllosilicates, and crystalline ferric oxide or hydroxide were found. Thermal emission spectra suggest that some minerals were in the tens of percent range.
[Wray, J., R. Milliken, C. Dundas, G. Swayze, J. Andrews-Hanna, A. Baldridge, M. Chojnacki, J. Bishop, B. Ehlmann, S. Murchie, R. Clark, F. Seelos, L. Tornabene, and S. Squyres. 2011. Columbus crater and other possible groundwater-fed paleolakes of Terra Sirenum, Mars. Journal of Geophysical Research E: Planets DOI: 10.1029/2010JE003694]
Image:Columbus Crater Layers.JPG, Columbus crater layers, as seen by 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 o ...
. This false-color image is about 800 feet across. Some of the layers contain hydrated minerals.
Image:Columbus Crater close-up.jpg, Close-up of Columbus crater, as seen by HiRISE
See also
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Groundwater on Mars
During past ages, there was rain and snow on Mars; especially in the Noachian and early Hesperian epochs. Some moisture entered the ground and formed aquifers. That is, the water went into the ground, seeped down until it reached a formation tha ...
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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 ...
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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 o ...
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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 o ...
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List of craters on Mars
__NOTOC__
This is a list of craters on Mars. Impact craters on Mars larger than exist by the hundreds of thousands, but only about one thousand of them have names. Names are assigned by the International Astronomical Union after petitioning by ...
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List of quadrangles on Mars
The surface of Mars has been divided into thirty cartographic quadrangles by the United States Geological Survey. Each quadrangle is a region covering a specified range of latitudes and longitudes on the Martian surface. The quadrangles are name ...
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Geological history of Mars
The geological history of Mars follows the physical evolution of Mars as substantiated by observations, indirect and direct measurements, and various inference techniques. Methods dating back to 17th century techniques developed by Nicholas Steno, ...
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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 ...
References
{{DEFAULTSORT:Columbus (Crater)
Memnonia quadrangle
Impact craters on Mars