Some of the Viking images sent back from Mars in the 1970s show tantalizing evidence of dendritic valley networks in some of the oldest terrains on the planet. One of the big questions ever since has been whether it might have rained early in Mars history. One of the ways of deciding whether the Mars valley networks might have been produced by rainfall is to find out how similar they are to valley networks on Earth, which we know are produced by rainfall. The standard method for analyzing drainage basins is comparison of the number of drainage segments per square kilometer (drainage density) and how extensively branched the network is (stream order). In this exercise, students calculate stream order for valley segments mapped by Hynek and Phillips (2003) using MOC/MOLA data. Students then use data on valley segment length and drainage basin area from Hynek and Phillips (2003) to calculate drainage density. They compare stream order and drainage density for the Mars site with similar calculations for areas on Earth and evaluate the question of whether valley networks on Mars might be consistent with rainfall on an early Mars, and what the uncertainties and limitations are in their conclusions.


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Higher Education,NSDL_SetSpec_380601,Undergraduate (Upper Division),Images/Maps/Visualizations,Undergraduate (Lower Division),Structural Visualizations,Geoscience,oai:nsdl.org:2200/20100502195744804T,Engineering,Water/Ice,Vocational/Professional Development Education,Mathematics,Education,Physics,Teaching with Visuals,Atmosphere/Climate,NSDL



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