Perchlorate: the threat to red hope

In soils with high concentrations of chloride it is converted to perchlorate in the presence of sunlight and/or ultraviolet light. This chemical compound is being the center of a big controversy now days, when human society is decided to find out if we are alone or not in this universe. It happens that perchlorate seems to be widespread in Mars dirt, a condition that will cause a lot of troubles in future space missions (tripulated or not) for different reasons. The most important of this reasons is related with the fact that this chemical compound (ClO4) is a salt comprised, derived from Cl and O2 and from perchloric acid, with a great solubility (except for compound KClO4). In Earth, is rare to find perchlorate in its natural form (except for the Atacama desert, and some other places in US, but with a very low density), but when it is artificially created it can be used in rocket fuel and also as part of thyroid diseases treatments. This is a good application of this compound here in our planet, but out there, the history is quite complex.

In Mars, mixtures of perchlorates with organic compounds are very reactive, a chemical characteristic that interferes with the hunting for possible traces of Martian life. As part of its mission, mars rover Curiosity heats up scoops of red planet dirt to test for organic carbon compounds (the building blocks of life in Earth). That heat can cause perchlorates in soil samples to set off a chemical reaction that destroys organics, as researches had discovered. “This may change the way we search for organics in the future on Mars” said Daniel Galvin, an astrobiology’s at NASA’S Goddard Space Flight Center in Greenbelt.

The Curiosity analysis system uses an instrument that breaks soil down into its chemical components and measures the concentration of each type of molecule, but when CLO4 is heated above 392 Fahrenheit it release pure oxygen and this causes organic molecules in samples to combust into CO2. For now, this is just another obstacle, but not the end of the story about looking sign of life in Mars. “Organic compounds can be analyzed if they stay preserved inside a more heat resistance material, or if the molecules could possibly be detected before the break down of the “killer salt”, Galvin said. Once more, we should remember that hope is the last thing we loose, and this is applicable even in nature and science.

Gannon, M. “Toxic Mars Chemical Throws wrench into search for read planet life” retrieved from www.space.com on October 2013.

By: Yahima Balboa, Vanessa Manso and Ana Diego