The Curiosity rover, formerly called the Mars Science Laboratory, will sniff for molecules associated with life as we know it (Image: NASA)

IF THERE’S life on Mars, we might smell it before we see it. A chemical involved in bad breath and flatulence in humans could lead us to alien microbes on the Red Planet.

The sulphur-containing molecule methyl mercaptan is naturally produced in significant quantities on Earth only by microbes, including some that make their pungent presence known in the human body. NASA’s next Mars rover is highly sensitive to the smelly chemical, which could betray the presence …