From AGU, December 12, 2001:

Martian Gullies: An Ecological Niche? Michael HechtJet Propulsion Laboratory

"(1) Sheltered geometry and high-latitude, pole-facing locations, cause gullies to accumulate a disproportionate amount of frost in winter, which persists into the spring. While the frost is predominantly CO2 (> 1 meter in depth), extrapolation of Viking observations suggests it may also contain centimeters of solid H2O.
(2) When the CO2 is gone, sunlight warms the ice to melting, wetting the surface soil under a crust of ice, resulting in flow or later deflation of soil. Regular resurfacing explains the absence of old, degraded gullies, even if they were initially formed by another mechanism.

The astonishing implication of this simple model is that wet soil may have been present seasonally in select locations for billions of years, dating from the time that Mars is argued to have been warm and wet. Moreover, microbial systems could easily enhance this environment through control of geometry, albedo, conductivity, and evaporation. "

Seems like all indications (like it or not) show that Mars was once warm and wet and that maybe life flourished and adapted to its changing conditions. We will have more data soon.

If Martian lifeforms are confirmed, Mars will be declared a biological sanctuary off limits to human explorers for perhas a century or two - like it or not, them's the facts.

:-)

Barry