The Phoenix lander has found a toxin in Mars soil that considerably decreases the odds of finding Martian life, Science.com reports. The chemical, perchlorate, is a harsh oxidizing agent often used in solid rocket fuel, so researchers are double checking to ensure it wasn’t carried from Earth. The results are especially surprising because Sunday’s tests revealed no sign of perchlorate.
"Initial analyses suggested Earth-like soil. Further analysis has revealed un-Earthlike aspects of the soil chemistry," says the project's principal investigator. Adds the Phoenix project manager: “When surprising results are found, we want to review and assure our extensive pre-launch contamination control processes covered this potential.” Even if the perchlorate is native to Mars, it wouldn’t totally rule out the possibility that life once existed, or still exists deep underground.