NASA says Mars toxin find doesn't rule out life

By Dan Whitcomb and Jennifer Martinez

LOS ANGELES (Reuters) - NASA scientists on Tuesday said the surprise discovery of a sometimes toxic chemical on the surface of Mars does not diminish the possibility of finding microbial life on the Red Planet and asked for patience while they study soil samples further.

The space agency also cautioned that further tests were required to confirm that dirt analyzed by the Phoenix Mars Lander contains perchlorate, an oxidizing substance used in rocket fuel that on Earth can be harmful to life, and rule out contamination by the spacecraft.

NASA's initial announcement that Phoenix had detected perchlorate in the soil at the arctic circle of Mars had been greeted in the media and on the Internet by speculation that such a discovery would dampen the likelihood of finding microbial life there.

"This has yet to be verified inside (Thermal and Evolved Gas Analyzer) instruments," Phoenix chief investigator Peter Smith said, adding that even if the discovery were confirmed "this does not preclude life on Mars. In fact it is a potential energy source."

"I ask that the media be patient with us," he said. "Let the science team proceed at a proper pace."

Phoenix is the latest NASA spacecraft sent to Mars to discover whether water ever flowed on Mars and if life, even in microbial form, exists or ever existed there.

Last week NASA said Phoenix had provided definitive proof that water exists on Mars after further tests on ice found by the lander in June.

'WE DON'T HAVE THE ANSWER'