Fire and ice - the right place to search for life?

Abstract

Creating a habitable environment is a complex process involving a wide variety of interacting processes. A prerequisite for any biological activity is an energy source. The terrestrial example of the black smokers shows how efficient geothermal processes are as an energy source. There is ample morphological evidence for continuous and episodic volcanic activity over the geological history of Mars. The youngest ages determined by the crater sizefrequency measurements are about 2 Ma suggesting that the volcanoes are potentially still active today. While there is no direct evidence for volcanic activity the likelihood for localized hot spot activity or hydrothermal systems is very high. We have shown recently using thermo-physical modeling that a morphologically identified glacial deposit on the northwestern flanks of Hecates Tholus contains very likely still a stagnant ice core. There are several units on Mars, especially on flanks of volcanic edifices, which based on morphological evidence may be glacial deposits and which are possibly still ice-cored. Combining these two findings provides an interesting option for a biological niche. Our modeling shows that variations in the climate and in the local internal heat flow due to ongoing volcanic activity can create a complex internal structure of these ice deposits. The ice deposits can effectively store volcanic gases. The enrichment of water ice with volcanic gases might form a nutrient rich environment which is protected by a dust cover and sealed by an enrichment of ice at the top. The implications for biological activity in these places deserve further attention.