Hunt for life on Mars just got harder: Toxic chemical in martian soil is burning away any evidence of living organisms on red planet Perchlorates have been shown to interfere with Curiosity's analysis When heated, the chemical causes a reaction that destroys organic carbon It is now believed perchlorates are prevalent throughout the Mars' surface A chemical in Martian soil could burn away any evidence of life before scientists are able to find it. Perchlorate, a salt made up of chlorine and oxygen, has been shown to interfere with techniques used by the Mars Curiosity rover to analyse soil samples. The chemical was first discovered last year when Curiosity trekked around Mars" Rocknest sand dune. Perchlorate, a salt made up of chlorine and oxygen, has been shown to interfere with techniques used by the Mars Curiosity rover to analyse soil samples When heated, perchlorates can cause a chemical reaction that destroys organic carbon. Daniel Glavin, an astrobiologist at Nasa Goddard Space Flight Center in Greenbelt, Maryland, said he now believes the troublesome perchlorates are likely prevalent throughout the Martian surface. 'The presence of perchlorates isn't good news for some of the techniques we're currently using with Curiosity,' said Mr Glavin. This may change the way we search for organics in the future on Mars. The Curiosity rover's Sample Analysis on Mars (SAM) system tests soil by heating them in an instrument, called a pyrolysis gas chromatograph mass spectrometer. The chemical was first discovered last year when Curiosity trekked around Mars' Rocknest sand dune These break the samples down into their chemical components and determine precisely how much of each of those components is present in the sample. Any perchlorate salts in the heated sample decompose as the temperature goes above 200 degrees Celsius and release pure oxygen. Perchlorates are the salts derived from perchloric acid (pictured). Hydrogen atom are shown in white, oxygen in red and chlorine in green Organic molecules in the sample exposed to this oxygen will then combust into carbon dioxide, destroying the molecular evidence of their presence. Luckily, Glavin said, some organic carbon would likely survive, either incased in more heat-resistant materials or detected before the breakdown of perchlorates. But Glavin noted that scientists can account for the destroyed organic carbon by assuming a certain amount of perchlorate will always be in the Martian soil. In future tests, scientists can calculate how much organic carbon burnt away with the decomposing perchlorates in order to estimate the original amount of organic material in the soil. 'It will be absolutely critical as we move on to other samples to compare them to the Rocknest dune to infer the presence or absence of Martian organic material,' said Glavin. Glavin added that Curiosity has the potential to avoid the perchlorate problem in the future by using techniques that do not involve heating the soil to the point where perchlorates break down. The rover already carries an apparatus capable of that, which it hasn't yet used.