The Martian surface may be even less hospitable to life than scientists had thought.
Ultraviolet (UV) radiation streaming from the sun “activates” chlorine compounds in the Red Planet’s soil, turning them into potent microbe-killers, a new study suggests.
These compounds, known as perchlorates, seem to be widespread in the Martian dirt; several NASA missions have detected them at a variety of locations. Perchlorates have some characteristics that would appear to boost the Red Planet’s habitability. They drastically lower the freezing point of water, for example, and they offer a potential energy source for microorganisms, scientists have said. [The Search for Life on Mars: A Photo Timeline]