Aug 4, 6:23 PM (ET)
By ALICIA CHANG
LOS ANGELES (AP) - Scientists say the Phoenix spacecraft has found a substance in the Martian soil that might be detrimental to possible life.
If confirmed, it could mean the soil may not be as friendly as once thought.
Scientists previously reported that the soil where Phoenix landed in May was Earth-like, containing nutrients such as magnesium, sodium and chloride.
The latest lab tests show the presence of an oxidizing substance.
NASA is investigating whether the substance could have gotten there by contamination.