UV Shielding Properties of Jarosite Vs. Gypsum: Astrobiological Implications for Mars
1G. Amaral, 2J. Martinez-Frias and 2,3L. Vázquez
1Departamento de Química Física I, Fac. Ciencias Químicas,
Universidad Complutense, 28040 Madrid, Spain
2Centro de Astrobiología (CSIC-INTA), Associated to the NASA Astrobiology Institute,
Ctra de Ajalvir km. 4, 28850 Torrejón de Ardoz, Spain
3Departamento de Matemática Aplicada, Facultad de Informática,
Universidad Complutense de Madrid, 28040 Madrid, Spain
: The discovery of liquid water-related sulfates on Mars is of great astrobiological interest. UV radiation experiments, using natural Ca and Fe sulfates (gypsum, jarosite), demonstrate a large difference in the UV protection capabilities of both minerals and also confirm that the mineralogical composition of the Martian regolith is a crucial shielding factor. It is demonstrated that a thin (500 μm-thick) sample of jarosite prevents UV transmission, providing suitable niches for life exploration.
Key words: UV shielding, Mars, jarosite, gypsum, astrobiology
World Applied Sciences Journal 2 (2): 112-116, 2007.