Noachis quadrangle

The Noachis quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Noachis quadrangle is also referred to as MC-27 (Mars Chart-27).[1]

The Noachis quadrangle covers the area from 300° to 360° west longitude and 30° to 65° south latitude on Mars. It lies between the two giant impact basins on Mars: Argyre and Hellas. Noachis is so densely covered with impact craters that it is deemed among the oldest landforms on Mars. When a location on Mars is as old, it is said to be Noachian in age.

In many places on Mars, buried craters are being exposed.[2] That is a crater formed long ago, then was buried, and is now being exposed. This takes place in Noachis, as Noachis is plenty old enough for this process to take place.

The first piece of human technology to land on Mars landed (crashed) in the Noachis quadrangle. The Soviet's Mars 2 crashed at 44.2° S and 313.2° W. It weighed about one ton. The automated craft attempted to land in a giant dust storm. To make conditions even worse, this area also has many dust devils.[3]

Contents

Scalloped topography

Certain regions of Mars display scalloped-shaped depressions. The depressions are believed to be the remains of an ice-rich mantle deposit. Scallops are created when ice sublimates from frozen soil. This mantle material probably fell from the air as ice formed on dust when the climate was different due to changes in the tilt of the Mars pole.[4] The scallops are typically tens of meters deep and from a few hundred to a few thousand meters across. They can be almost circular or elongated. Some appear to have coalesced, thereby causing a large heavily pitted terrain to form. The process of producing the terrain may begin with sublimation from a crack because there are often polygon cracks where scallops form.[5][6]

Dust Devil Tracks

Many areas on Mars experience the passage of giant dust devils. A thin coating of fine bright dust covers most of the Martian surface. When a dust devil goes by it blows away the coating and exposes the underlying dark surface creating tracks. Dust devils have been seen from the ground and from orbit. They have even blown the dust off of the solar panels of the two Rovers on Mars, thereby greatly extending their lives.[7] The twin Rovers were designed to last for 3 months, instead they have lasted more than six years and are still going. The pattern of the tracks have been shown to change every few months.[8] The image below of Russel Crater shows changes in dust devil tracks over a period of only three months, as documented by HiRISE. Other Dust Devil Tracks are visible in the picture of Frento Vallis.

Craters

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.[9] The peak is caused by a rebound of the crater floor following the impact.[10] Sometimes craters will display layers. Craters can show us what lies deep under the surface.

Sand Dunes

Gallery

References

  1. ^ Davies, M.E.; Batson, R.M.; Wu, S.S.C. “Geodesy and Cartography” in Kieffer, H.H.; Jakosky, B.M.; Snyder, C.W.; Matthews, M.S., Eds. Mars. University of Arizona Press: Tucson, 1992.
  2. ^ Mars Space Flight Facility (17 March 2004). "Exhumed Crater (Released 17 March 2004)". Arizona State University. http://themis.asu.edu/zoom-20040317a. Retrieved 19 December 2011. 
  3. ^ Hartmann, W. 2003. A Traveler's Guide to Mars. Workman Publishing. NY, NY.
  4. ^ Head, J. et al. 2003. Recent ice ages on Mars. Nature:426. 797-802.
  5. ^ Lefort, A. et al. 2010. Scalloped terrains in the Peneus and Amphitrites Paterae region of Mars as observed by HiRISE. Icarus: 205. 259-268.
  6. ^ www.sciencedirect.com/science/journal/00191035
  7. ^ "Press Release Images: Spirit". National Aeronautics and Space Administration. 12 April 2007. http://marsrovers.jpl.nasa.gov/gallery/press/spirit/20070412a.html. Retrieved 19 December 2011. 
  8. ^ "Ken Edgett". National Aeronautics and Space Administration. 2001. http://mars.jpl.nasa.gov/spotlight/KenEdgett.html. Retrieved 19 December 2011. 
  9. ^ http://www.lpi.usra.edu/publications/slidesets/stones/
  10. ^ Hugh H. Kieffer (1992). Mars. University of Arizona Press. ISBN 9780816512577. http://books.google.com/books?id=NoDvAAAAMAAJ. Retrieved 7 March 2011. 

See also