IF THERE’S life on Mars, we might smell it before we see it. A chemical involved in and 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 , 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 of Martian microbes, says Steven Vance of NASA’s Jet Propulsion Laboratory in Pasadena, California.
The instrument in question is the , which will fly on the – set to land on Mars in 2012. TLS was designed to analyse the carbon isotopes in Mars’s methane to search for signs that the gas has a biological origin. But the isotope tests might produce ambiguous results, so finding methyl mercaptan would help bolster the case for Martian microbes, Vance says. TLS should be able to detect the gas at concentrations below 100 parts per billion, according to his team’s tests on a similar spectrometer ().
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“The rover should be able to detect the biomarker gas at concentrations below 100 parts per billion”
The researchers are also planning to check TLS’s sensitivity to other gases produced by terrestrial microbes, like ethane. “We’re demonstrating its ability to look at additional biomarkers and hopefully that will help us in our search for life,” Vance says.
Kenneth Nealson at the University of Southern California in Los Angeles, who was not involved in the study, says finding several potential indicators of life in the same place would make it a good target for follow-up missions. “I think you’d get pretty excited,” he says. “You’d want to make sure that the next lander would spend time at that site.”
