Chapter 8 - Habitability and Biomarker Preservation in the Martian Near-Surface Radiation Environment

Abstract

Numerical models and measurements at the Martian surface show that ionizing radiation in the form of galactic cosmic rays and solar energetic particles impinging on the planet's surface and results in the formation of secondary ionizing radiation that affects the top dozen meters of the subsurface. In this brief review, we quantitatively model this secondary ionizing radiation as function of energy and depth. We then use basic physical arguments to explain the effect of this secondary ionization on organic molecules and cells and estimate microbe survival times as function of depth and soil type. Finally, we compare our calculated results on Deinococcus radiodurans survival time with other studies that have been reported in the literature.