The Valles Marineris is a vast system of canyons on the surface of the planet Mars, just south of its equator at 11.6° south and 70.7° west. It is easily one of the most recognizable features to a planetary geologist and within it lie the largest canyons known (so far) by mankind. With a minimum depth of over six kilometers, this canyon is sure to contain vast amounts of geological data.
One of the key ingredients required to harbour life is the presence of water, a concept that is the driving force behind many planetary studies. "Follow the water" is a saying often used by NASA in their education outreach programs. The idea being that where there is water, there might be life.
Therefore an ideal location to analyze this paradigm would be one that contains land-forms and features typically seen in sub-aquatic, fluvial environments, which as it just so happens, perfectly characterizes the appearance of some of the features in the Valles Marineris. Many discussions throughout the years have generally concluded water existed on Mars at one time or another. So while it is generally accepted that there is water, where this water is and where it has been remains hotly debated. By examining possible scenarios for how this massive canyon system was created and changed over time, more accurate hypotheses can be drawn as to the fate of Martian water.