World Library  
Flag as Inappropriate
Email this Article

Dawes (Martian crater)

Article Id: WHEBN0022041827
Reproduction Date:

Title: Dawes (Martian crater)  
Author: World Heritage Encyclopedia
Language: English
Subject: Sinus Sabaeus quadrangle, Transit of Venus from Mars, Asopus Vallis, Ganges Mensa, Moons of Mars
Collection: Impact Craters on Mars, Sinus Sabaeus Quadrangle
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Dawes (Martian crater)

Dawes Crater is located in the Sinus Sabaeus quadrangle of Mars, at [1]. It is about 191 km (119 mi) in diameter, and was named after William R. Dawes, a British astronomer (1799–1868)[3] who was ahead of his time in believing that Mars only had a thin atmosphere. Dawes presumed that the atmosphere of Mars was thin because surface markings on the planet could easily be seen.[4]

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.[5] The peak is caused by a rebound of the crater floor following the impact.[6] 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.

Why are Craters important?

The density of impact craters is used to determine the surface ages of Mars and other solar system bodies. [7] 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. [8] Studies on the earth have documented that cracks are produced and that secondary minerals veins are deposited in the cracks.[9] [10] [11] Images from satellites orbiting Mars have detected cracks near impact craters.[12] Great amounts of heat are produced during impacts. The area around a large impact may take hundreds of thousands of years to cool.[13] [14] [15]

See also

References

  1. ^ Blue, Jennifer. "Dawes". Gazetteer of Planetary Nomenclature. USGS Astrogeology Research Program.
  2. ^ Blue, Jennifer. "Dawes". Gazetteer of Planetary Nomenclature. USGS Astrogeology Research Program.
  3. ^ "Gazetteer of Planetary Nomenclature".  
  4. ^ Glasstone, S. (1968). The Book of Mars.  .
  5. ^ http://www.lpi.usra.edu/publications/slidesets/stones/
  6. ^ Hugh H. Kieffer (1992). Mars. University of Arizona Press.  
  7. ^ http://www.lpi.usra.edu/publications/slidesets/stones/
  8. ^ http://www.indiana.edu/~sierra/papers/2003/Patterson.html.
  9. ^ 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
  10. ^ http://www.ingentaconnect.com/content/arizona/maps/2005/00000040/00000012/art00007
  11. ^ Pirajno, F. 2000. Ore Deposits and Mantle Plumes. Kluwer Academic Publishers. Dordrecht, The Netherlands
  12. ^ 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
  13. ^ name="news.discovery.com"
  14. ^ 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
  15. ^ Segura, T, O. Toon, A. Colaprete, K. Zahnle. 2002. Environmental Effects of Large Impacts on Mars. Science: 298, 1977-1980.
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 



Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.