The issue of past life on Mars

Ron Greeley video
Ron Greeley audio

I think the fact we see a very complex history being displayed at the Pathfinder site, involving changes in climate, involving large quantities of liquid water, involving volcanic activity that's more complicated than we suspected before. All of these comes to play, come to bear on the question of life and I would say it enhances the possibilities of life on Mars. It doesn't mean that life did originate there, that it started there, or that it exists there today. It simply means that the environmental conditions, the factors that are conducive to life are more favorable than we might have thought before.