Evidence that the reactivity of the martian soil is due to superoxide ions.
The Viking Landers were unable to detect evidence of life on Mars but, instead, found a chemically reactive soil capable of decomposing organic molecules. This reactivity was attributed to the presence of one or more as-yet-unidentified inorganic superoxides or peroxides in the martian soil. Using electron paramagnetic resonance spectroscopy, we show that superoxide radical ions (O2-) form directly on Mars-analog mineral surfaces exposed to ultraviolet radiation under a simulated martian atmosphere. These oxygen radicals can explain the reactive nature of the soil and the apparent absence of organic material at the martian surface.
Yen
A S
AS
Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA. Albert.Yen@jpl.nasa.gov
Kim
S S
SS
Hecht
M H
MH
Frant
M S
MS
Murray
B
B
D000538:Aluminum Silicates / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy; D018559:Exobiology; D005118:Extraterrestrial Environment; D007477:Ions; D018535:Mars; D010100:Oxygen; D017680:Potassium Compounds / Q000737:chemistry; D012987:Soil; D013481:Superoxides / Q000032:analysis / Q000737:chemistry
D000538:Aluminum Silicates; D007477:Ions; D017680:Potassium Compounds; D012987:Soil; D013481:Superoxides; C016447:feldspar; D010100:Oxygen