Salt in Mars' soil stirs debate

Traces of a rocket fuel ingredient found in the Martian soil would not necessarily hinder potential life, mission scientists said Tuesday.

NASA's Phoenix spacecraft earlier this month detected the chemical perchlorate, a highly oxidizing salt, in soil samples dug from near the Martian surface. On Earth, it can be found naturally in the arid Atacama Desert in Chile, where extreme organisms use it as an energy source.

“We know that microbes can exist quite happily in oxidizing conditions,” said Phoenix scientist Richard Quinn of the NASA Ames Research Center. “The story possibly could turn out to be the same for Mars. We don't know yet.”

The surprising find comes less than two months after scientists reported that the soil near Mars' north pole was Earth-like where plants such as asparagus, green beans and turnips could thrive. The presence of perchlorate, if confirmed, would appear to make the soil more exotic than previously believed. But scientists insisted that has no bearing on the red planet's habitability.

“In itself, it is neither good nor bad for life,” chief scientist Peter Smith of the University of Arizona in Tucson said of the chemical.

Some researchers who have no role in the $420 million mission were less enthusiastic.

“Perchlorate is not a particularly nice thing to find in the soil,” said astrobiologist Kenneth Nealson of the University of Southern California. “No one hunting for life would be happy to see it in any sort of abundance.”