Mars Soil May Be Toxic to Microbes

[Judi Lynn]

By Mike Wall, Space.com Senior Writer | July 6, 2017 09:40am ET


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]

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]

But the new study, by Jennifer Wadsworth and Charles Cockell — both of the U.K. Centre for Astrobiology at the University of Edinburgh in Scotland — paints perchlorates in a different light. The researchers exposed the bacterium Bacillus subtilis, a common spacecraft contaminant, to perchlorates and UV radiation at levels similar to those found at and near the Martian surface. (Because Mars' atmosphere is just 1 percent as thick as that of Earth, UV fluxes are much higher on the Red Planet than on Earth.)

More:
https://www.space.com/37402-mars-life-soil-toxic-perchlorates-radiation.html?utm_source=notification