The Effect of Martian Surface Geometry on Ultraviolet Fluxes

Introduction: The atmosphere of Mars, unlike that of the Earth, does little to attenuate incoming ultraviolet radiation. Such large amounts of ultraviolet radiation are known not only to sterilize the hardiest of terrestrial organisms within minutes [1], but to chemically alter the soil such that organic molecules in the upper few cm are rapidly destroyed [2]. Thus the survival of any putative Martian life near the surface depends to a large extent on how much ultraviolet radiation is received at its location. As such, variations in smallscale geometry of the surface such as pits, trenches, flat faces and overhangs can have a significant effect on the observed flux and create “safe havens” for organisms. Furthermore, by quantifying this reduction in radiation we can better pick targets for landed missions knowing which geometries offer us the best chance of uncovering such a safe haven. Method: A theoretical approach was taken to determine the appropriate fluxes. A numerical 1-Dimensional model based upon the doubling and adding method