1. Morphological Evidence for Water on Mars

2. Overview Pictorial comparison of features on Earth and Mars Gullies Alluvial fans Sedimentary layers Crossbedding Vugs Lake Missoula

3. Gullies USGS image of Meteor Crater, AZMars Global Surveyor image of Mars Gullies on Earth are formed by flowing water cutting through the soil. On Mars, frozen water near the surface is thought to melt and run to form gullies before refreezing or evaporating.

4. Alluvial Fans USGS image of alluvial fan in Mojave Desert Mars Global Surveyor image of alluvial fan While alluvial fans on Earth are the result of sedimentary build up at the mouths of rivers, alluvial fans on Mars are found almost exclusively on crater rims.

5. Sedimentary Layers Sedimentary layers like this are usually deposited where lakes and other bodies of water occurred on Earth. Mars Global Surveyor image of Candor Chasma

6. Crossbedding Mars Opportunity rover image of crossbedding Image of crossbedding on Earth Common on Earth, this particular type of crossbedding (festoon) is the result of deposits made by flowing water.

7. Vugs Mars Opportunity rover image of vugs Vugs in rock sample from Earth Vugs form when mineral deposits in rocks are eroded away by flowing water, leaving irregularly shaped holes behind.

8. Ripples Lake Missoula ripples Mars Opportunity rover image of ripples

9. Boulder Fields Scablands

10. Coulees Grand Coulee, Montana Coulees constitute the largest channels and are among the most spectacular erosional features in the scablands. Echus Chasma - Mars

11. River System Scablands - Eastern Washington Mars

12. Summary Certain features on Mars are similar to features commonly found on Earth. The features on Earth are known to have been caused by the existence of water in those locations. Most scientists now believe that these features on Mars are evidence that water has existed on Mars in the past and may, in fact, still exist below the surface today.

13. Bibliography Anderson, P. (2006, January 08). Festoon cross-bedding. Retrieved Jun 10, 2008 from The Meridian Journal web site: http://themeridianijournal.blogspot.com/2006/01/festoon-cross-bedding.htmlhttp://themeridianijournal.blogspot.com/2006/01/festoon-cross-bedding.html Bortman, H. (2004, March 03). Evidence of water found on Mars. In Astrobiology Magazine. Retrieved June 10, 2008 from NASA web site: http://astrobio.net/news/article859.htmlhttp://astrobio.net/news/article859.html Nemiroff, R and Bonnell, J. (2003, February 05). Unusual Gullies and Channels on Mars. In Astronomy Picture of the Day. Retrieved June 10, 2008 from NASA website: http://antwrp.gsfc.nasa.gov/apod/ap030205.html http://antwrp.gsfc.nasa.gov/apod/ap030205.html O’Brien, M. (2000, June 22). Visual evidence suggests water springs on Mars. Retrieved June 10, 2008 from CNN website: http://archives.cnn.com/2000/TECH/space/06/22/mars.water.03/http://archives.cnn.com/2000/TECH/space/06/22/mars.water.03/ Webster, G. and Savage, D. (2004, March 02). Opportunity rover finds strong evidence Meridiani Planum was wet. Retrieved June 10, 2008 from NASA website: http://marsrover.nasa.gov/newsroom/pressreleases/20040302a.html http://marsrover.nasa.gov/newsroom/pressreleases/20040302a.html Craters may control alluvial fan formation on Mars. (2005, October 31). In the Jounral of Young Investigators. Retrieved June 10, 2008 from The Journal of Young Investigators web site: http://www.jyi.org/news/nb.php?id=600 http://www.jyi.org/news/nb.php?id=600