06/03/02
Essalm Heggy	Observatoire de Bordeaux
2 rue de l'observatoire	Non-teacher
33270	Floirac, France

Presentation 1 : Poster
H.O.U TO SEEK WATER IN THE MARTIAN SUBSURFACE
Essam Heggy
Among a lot of evidence of water presence in the Martian underground, ejecta crater are on of the most direct ways to prove the presence of ice in the Martian subsurface covered by a layer of volcanic materials. Craters with fluid-like ejecta help us to estimate the presence and depth of the ice rich layer and find enviroments where water may probably be present in deep. the edge of the craters can also help us to under stand some aspect of the Martian atmosphere and erosion processes. We propose here a very simple scheme that should help student to better understand the evidence of ice and water presence on an other planete by observing the form of crater and how we can use this information to trace ice and water in the Martian underground. Student at the end of the lesson should be able to differentiate and argument the difference between the Martian and Lunar craters where we can note the sharp edge of the crater since there is no wind erosion on the moon (as there is no atmosphere) and the absence of ejected lobes (as there is no underground ice). The materials used in this demostrations are free and already available on the NASA website. We will use Mars Orbital Camera images of Martian craters and some Apollo images for lunar craters. We have developed a FORTRAN module able to recognize forms on image (FITS format) this could be integrated in the user interface H.O.U to help student to track craters with lobes on Mars surface images and thus deffines local region where ice migth be hidden below the surface at depth starting from 300 meters.
Presentation 2 : Poster
Fluvial like features on Mars and Earth deserts
E.Heggy
The exercise is based on a visual comparaison between images of the West-Egyptian desert and some regions on Mars. Both type of images show dry rivers structures in a very arid context indicating that in the past enviromental conditions in those regions allowed the presence of surface liquid water and probably life. An open debat between students on the similarity of those dry fluvial-like structures on both type of images should introduce to them the basis of the global enviromental changes that a planet may undergo along time and how fragile and important is a hydrosphere. The materials required for this exercise are free and available on several web sites.

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