The headline: "Mars may not be lifeless, say scientists"
"Carbon-rich organic molecules, which serve as the building blocks of life, may be present on Mars after all, say scientists - challenging a widely-held notion of the Red Planet as barren."
"After mixing the soil with perchlorate and heating it, they found that the gases produced were carbon dioxide and traces of chloromethane and dichloromethane - just like the gases released by the chemical reactions after the Viking landers heated the Martian soil more than three decades ago."
"'Our results suggest that not only organics, but also perchlorate, may have been present in the soil at both Viking landing sites,' said the study's lead author, Rafael Navarro-González of the National Autonomous University of Mexico, Mexico City."
"This doesn't say anything about the question of whether or not life has existed on Mars, but it could make a big difference in how we look for evidence to answer that question," said Chris McKay of Nasa's Ames Research Center, California.
Keep looking, then.