Science: Curiosity’s Sample Analysis at Mars (SAM) instrument package has detected three chloromethane compounds in soil samples. The compounds are three of the simplest possible carbon molecules, made of a single atom of carbon bonded with 1, 2, or 3 chlorine atoms. Principle investigator Paul Mahaffy of NASA’s Goddard Space Flight Center says the compounds were likely created in SAM. The instrument heats soil samples, so it probably caused the decomposition of several natural compounds in the soil, which resulted in the chlorination of the carbon atoms. NASA’s researchers now have to try to determine whether the original compounds were organic in nature and whether they were originally formed on Mars or deposited there. Similar experiments by the Viking landers in the 1970s also detected chloromethane molecules, but the researchers believed them to be the result of contamination from solvents used for cleaning the landers.