Bacolor (crater)

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Bacolor Crater
Bacolor Crater Ejecta.JPG
Bacolor Crater Ejecta, as seen by HiRISE. Scale bar is 1000 meters long.
Planet Mars
Coordinates 33°00′N 241°24′W / 33°N 241.4°W / 33; -241.4Coordinates: 33°00′N 241°24′W / 33°N 241.4°W / 33; -241.4
Diameter 20.8 km
Eponym a town in the Philippines

Bacolor Crater is a crater in the Casius quadrangle of Mars, located at 33 North and 241.4 West. It is 20.8 km in diameter and was named after a town in the Philippines.[1]

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.[2] The peak is caused by a rebound of the crater floor following the impact.[3] If one measures the diameter of a crater, the original depth can be estimated with various ratios. Because of this relationship, researchers have found that many Martian craters contain a great deal of material; much of it is believed to be ice deposited when the climate was different.[4] Sometimes craters expose layers that were buried. Rocks from deep underground are tossed onto the surface. Hence, craters can show us what lies deep under the surface.

Studies on the earth have documented that cracks are produced and that secondary minerals veins are deposited in the cracks.[5][6][7] Images from satellites orbiting Mars have detected cracks near impact craters.[8] Great amounts of heat are produced during impacts. The area around a large impact may take hundreds of thousands of years to cool.[9][10][11]

Why are Craters important?[edit]

The density of impact craters is used to determine the surface ages of Mars and other solar system bodies.[2] The older the surface, the more craters present. Crater shapes can reveal the presence of ground ice.

The area around craters may be rich in minerals. On Mars, heat from the impact melts ice in the ground. Water from the melting ice dissolves minerals, and then deposits them in cracks or faults that were produced with the impact. This process, called hydrothermal alteration, is a major way in which ore deposits are produced. The area around Martian craters may be rich in useful ores for the future colonization of Mars.[12]

See also[edit]

References[edit]

  1. ^ http://planetarynames.wr.usgs.gov/
  2. ^ a b http://www.lpi.usra.edu/publications/slidesets/stones/
  3. ^ Hugh H. Kieffer (1992). Mars. University of Arizona Press. ISBN 978-0-8165-1257-7. Retrieved 7 March 2011. 
  4. ^ Garvin, J., et al. 2002. Global geometric properities of martian impact craters. Lunar Planet Sci. 33. Abstract @1255.
  5. ^ Osinski, G, J. Spray, and P. Lee. 2001. Impact-induced hydrothermal activity within the Haughton impact structure, arctic Canada: Generation of a transient, warm, wet oasis. Meteoritics & Planetary Science: 36. 731-745
  6. ^ http://www.ingentaconnect.com/content/arizona/maps/2005/00000040/00000012/art00007
  7. ^ Pirajno, F. 2000. Ore Deposits and Mantle Plumes. Kluwer Academic Publishers. Dordrecht, The Netherlands
  8. ^ Head, J. and J. Mustard. 2006. Breccia Dikes and Crater-Related Faults in Impact Craters on Mars: Erosion and Exposure on the Floor of a 75-km Diameter Crater at the Dichotomy Boundary. Special Issue on Role of Volatiles and Atmospheres on Martian Impact Craters Meteoritics & Planetary Science
  9. ^ name="news.discovery.com"
  10. ^ Segura, T, O. Toon, A. Colaprete, K. Zahnle. 2001. Effects of Large Impacts on Mars: Implications for River Formation. American Astronomical Society, DPS meeting#33, #19.08
  11. ^ Segura, T, O. Toon, A. Colaprete, K. Zahnle. 2002. Environmental Effects of Large Impacts on Mars. Science: 298, 1977-1980.
  12. ^ http://www.indiana.edu/~sierra/papers/2003/Patterson.html.