  Since Viking has conducted its life detection experiments on Mars, many
missions have enhanced our knowledge about the environmental conditions on the
Red Planet. However, the Martian surface chemistry and the Viking lander
results remain puzzling. Non-biological explanations that favor a strong
inorganic oxidant are currently favored (e.g., Mancinelli, 1989; Quinn and
Zent, 1999; Klein, 1999, Yen et al., 2000), but problems remain regarding the
life time, source, and abundance of that oxidant to account for the Viking
observations (Zent and McKay, 1994). Alternatively, a hypothesis favoring the
biological origin of a strong oxidizer has recently been advanced (Houtkooper
and Schulze-Makuch, 2007). Here, we report about laboratory experiments that
simulate the experiments to be conducted by the Thermal and Evolved Gas
Analyzer (TEGA) instrument of the Phoenix lander, which is to descend on Mars
in May 2008. Our experiments provide a baseline for an unbiased test for
chemical versus biological responses, which can be applied at the time the
Phoenix Lander transmits its first results from the Martian surface.
