Phoenix spacecraft has found a highly oxidizing substance in the Martian soil that may not be as friendly to life as once thought, NASA scientists said on Monday.

This image taken July 14, 2008 by the Surface Stereo Imager on Phoenix Mars Lander shows the silver colored rasp protruding from the lander's robotic arm scoop.[Xinhua/Reuters Photo]

Two samples analyzed within the last month by Phoenix's Microscopy, Electrochemistry and Conductivity Analyzer, or MECA, suggest that the Martian dirt may contain perchlorate, a highly oxidizing substance, which would create a harsh environment for any potential life.

Here on Earth, high doses of perchlorate can interfere with thyroid hormone production, which can harm babies in the womb.

MECA's previous analysis indicated the soil where Phoenix landed in May was earthlike in certain respects, including its pH and the presence of certain minerals, such as magnesium, sodium and chloride.

Phoenix's MECA wet chemistry experiment detected the chemical. Phoenix team was waiting for the craft's gas analyzer, TEGA, to confirm the finding.

NASA said the team was also working to rule out the possibility that the perchlorate readings could be contamination brought from Earth.

A NASA handout image shows the Robotic Arm on NASA's Phoenix Mars Lander with a sample of martian soil.[Xinhua/AFP Photo]

(Xinhua News Agency via agencies August 5, 2008)