The interest about water and waterpaths in the red planet is quite old. In the late 19th century the Italian astronomer Giovanni Schiaparelli published a map of mars which looked like a river delta with several islands (Image 1). During the first decade of the 20th century the American astronomer Percival Lowell published books and maps with a detailed description of what he termed the "non-natural features". Lowell's channels were more like a network of artifitial adduction channels (Image 2). Such publications popularized the belief that these markings showed that Mars sustained intelligent life forms. Later studies showed that such channels were product of optical illusions due to technical limitations of the equipment of that time.

Image 1. Martian channels reported by Schiaparelli (left) and Lowell (right)

Nevertheless, some years ago satellite missions revealed evidence of water in the form of river beds, geological forms that are typically formed from large amounts of water and frozen water (i.e., ice) in the martian poles.





Last March 7 2013, a team of scientists published a 3D reconstruction of buried flood channels in the Marte Vallis system, located in the Elysum Planitia. Using the Shallow Radar (SHARAD) sounder on the Mars Reconnaissance Orbiter, scientists were able to produce a tomographic visualization of the buried Marte Vallis channels. The SHARAD data revealed a complex channel system consisting of a broad ~40 km wide main channel that is adjacent to a raised bench, 120 km in width and incised by anastomosing channels formed around four streamlined islands. The main channel has an estimated depth between 69 - 113 m, which is comparable to the depth of the largest megaflood event on Earth. Such channels may have been generated by an ancient mega-flood event due to the release of groundwater.

Image 2. 3D visualization of the buried Marte Vallis channels beneath the Martian surface

Scientists are now studying the source and scale of the channels, in order to comprehend Martian hydrologic activity and determine whether such floods could be related climate change on our planetary neighbour. Topographic data is already available, along with estimation of water volume. Now, I Wonder if it is reasonable to imagine that future studies will probably apply hydrologic and hydraulic modelling techniques in order to understand the past hydrological events that happened in the red planet. Will it possible to apply current modelling software, e.g. HMS, MODFLOW or RAS, to Mars? Which modifications would be required? Maybe the lower gravity would induce modifications to some parameters such as different manning or Froude number. Anyway, I think it opens a new door of opportunities for hydrological and planetary sciences



