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 no ...

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 th ...

, 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 dr ...

, 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 i ...

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, a ...

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 octahed ...

, hydrated sulfates including

alunite Alunite is a hydroxylated aluminium potassium sulfate mineral, formula K Al3( S O4)2(O H)6. It was first observed in the 15th century at Tolfa, near Rome, where it was mined for the manufacture of alum. First called ''aluminilite'' by J.C. De ...

and possibly jarosite. Further study concluded that

, 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

References

{{DEFAULTSORT:Columbus (Crater) Memnonia quadrangle Impact craters on Mars

Layers

See also

References