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Amino acid photostability on the Martian surface
Author(s) -
KATE Inge Loes,
GARRY James R. C.,
PEETERS Zan,
QUINN Richard,
FOING Bernard,
EHRENFREUND Pascale
Publication year - 2005
Publication title -
meteoritics and planetary science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.09
H-Index - 100
eISSN - 1945-5100
pISSN - 1086-9379
DOI - 10.1111/j.1945-5100.2005.tb00183.x
Subject(s) - mars exploration program , regolith , martian , astrobiology , martian surface , flux (metallurgy) , planet , exploration of mars , ultraviolet , organic molecules , materials science , martian soil , chemistry , environmental science , molecule , physics , organic chemistry , astrophysics , optoelectronics
— In the framework of international planetary exploration programs, several space missions are planned to search for organics and bio‐signatures on Mars. Previous attempts have not detected any organic compounds in the Martian regolith. It is therefore critical to investigate the processes that may affect organic molecules on and below the planet's surface. Laboratory simulations can provide useful data about the reaction pathways of organic material at Mars' surface. We have studied the stability of amino acid thin films against ultraviolet (UV) irradiation and use those data to predict the survival time of these compounds on and in the Martian regolith. We show that thin films of glycine and D‐alanine are expected to have half‐lives of 22 ± 5 hr and of 3 ± 1 hr, respectively, when irradiated with Mars‐like UV flux levels. Modelling shows that the half‐lives of the amino acids are extended to the order of 10 7 years when embedded in regolith. These data suggest that subsurface sampling must be a key component of future missions to Mars dedicated to organic detection.