Hydrogen peroxide on Mars: Observations, interpretation and future plans

Ever since the Viking mass spectrometer failed to detect organics on the surface of Mars in 1976 (Biemann et al., 1976), hydrogen peroxide (H2O2) has been suggested as a possible oxidizer of the Martian surface (Oyama and Berdahl, 1977). However, the search for H2O2 on Mars was unsuccessful for three decades. In 2003, hydrogen peroxide was finally detected using two ground-based independent techniques, first with submillimeter heterodyne spectroscopy (Clancy et al., 2004) and then again with thermal infrared imaging spectroscopy (Encrenaz et al., 2004). The latter method has been used to simultaneously monitor the abundances and spatial distributions of H2O2 and H2O on Mars as a function of the seasonal cycle. Comparison with the LMD Global Climate Model (GCM) shows that the observations favor simulations taking into account heterogeneous chemistry (Lefèvre et al., 2008). It has been suggested (Delory et al., 2006; Atreya et al., 2006, 2007) that large amounts of hydrogen peroxide could be generated by triboelectricity during dust storms or dust devils. This paper presents a review of the present H2O2 dataset and an analysis of observability of peroxide during such events using present and future means.