NASA scientists said on Tuesday that the Phoenix Mars Lander has detected the apparent presence of a chemically reactive salt called perchlorate in the Martian soil. Perchlorate is a toxic material that's used in rocket fuel, but the scientists said its presence doesn't lessen the possibility that Mars has or once had some kind of life on it. VOA's Art Chimes reports.

Microscopic view of Martian soil at the tip of the Phoenix lander's robotic arm scoop [Credit: NASA/JPL-Caltech/ University of Arizona/Max Planck Institut]

Perchlorate sounds like nasty stuff. It's used in pyrotechnic devices like fireworks and automobile air bags. It's found in soil here on earth mainly in extremely dry climates, including the Atacama Desert in Chile, where the soil has been described as Mars-like.

But just because it's toxic doesn't mean that life can't exist around perchlorates, says Phoenix scientist Sam Kounaves of Tufts University.

"There are actually a large number of plants that ... grow in perchlorate at certain levels," he said. "It's a benign chemical in terms of most organisms."

Finding perchlorate was a surprise to the Phoenix scientists, says principal investigator Peter Smith of the University of Arizona.

"Perchlorate is something that caught me by surprise. ... I had to go straight back to the textbooks and figure out what this material is. So it's been quite an education over the last few weeks."

The Phoenix lander was designed to look for signs of water — not perchlorates or signs of life.

Smith said Tuesday's conference call briefing for reporters was a break with scientific tradition since the analysis of the apparent perchlorate findings was still a work in progress, with more confirmation tests still needed.

NASA organized the briefing after several days of Internet rumors about some big discovery on Mars, so big that even the White House had been given a special briefing. But NASA spokesman Dwayne Brown said there was nothing to the reports.

"Neither the White House nor the president's science advisor was briefed on this," he told reporters.

The scientists still have more tests to do to confirm the presence of perchlorates. They're also unclear if the small area around the Phoenix lander is representative of the rest of Mars.