NASA's Phoenix Lander team said this week it has found a toxic chemical in the soil of Mars' northern hemisphere, where it has previously confirmed the existence of water.
The University of Arizona-based team believes the chemical is perchlorate, an oxidant typically used in solid rocket fuel. The scientists are still analyzing the soil sample to make sure it wasn't brought to Mars from Earth, according to a statement. But if the oxidant is native, it would bar the possibility of life there.
"While we have not completed our process on these soil samples, we have very interesting intermediate results," Peter Smith, Phoenix's principal investigator at the University of Arizona, said in a statement. "Initial...analysis suggested Earth-like soil. Further analysis has revealed un-Earthlike aspects of the soil chemistry."
According to a report from CNN, the Viking 1 and 2 lander missions in the 1970s found oxidants in the soil that led many scientists to believe there could be no life on Mars.