Date and Time
Bath Royal Literary and Scientific Institution, 16-18 Queen Square, Bath BA1 2HN
Knowledge accumulated from previous and ongoing spacecraft missions to Mars shows that the surface has been frozen and sterile for most of the planet’s history. However, Mars has a long history of volcanic activity, and our recent work shows that any one giant volcano is likely to have had active periods lasting for ~1 million years interspersed with dormant periods lasting ~100 million years. Counts of impact craters on lava flows on the flanks and summits of the volcanoes show that some eruptions are no more than 10-30 million years old, so there is every reason to think that eruptions may occur again in the future. However, the long dormant periods mean that volcanic centres may not be places where primitive organisms might have evolved and survived on Mars. A better candidate is the system of liquid water aquifers trapped at 5-10 km depth below the frozen crust and maintained by global geothermal heat. Violent but short-lived water floods occur when volcanic eruptions crack the crust, and it is in the floors of the great channel systems carved by these floods that we should be looking for the organic residue of possible life on Mars.
View Larger Map