Study: Infant Mars Suited for Life

Ancient clays bearing telltale signs of standing water indicate the most likely time for life to have developed on Mars was about four billion years ago, before a cataclysmic global change left the planet cold, dry and plagued with acid water, researchers said Thursday.

Fair enough. But the big news in this story, at least to me, is the notion that Mars lost its atmosphere via some catastrophe, rather than simply losing it as a result of some combination of weaker gravity and lots of radiation due to no magnetic field. Or have I been way off on that this whole time?

Between four billion and 3.5 billion years ago, Mars underwent a dramatic change. The shift may have been triggered by massive volcanic eruptions that spewed sulfur into the atmosphere, which then rained down on the planet's surface.