The problem is, perchlorates can also be toxic to bacteria, depending on the presence of ultraviolet radiation-which, unfortunately, bathes Mars continuously. Science fiction authors have been imagining life on Mars for generations, and scientists have been looking for signs of life on the red planet for decades. If they can't survive there, it significantly lowers our chances of finding life on Mars - life that looks similar to organisms on Earth at least.
It's a type of salt found on the planet's soil - and when exposed to Mars-like conditions, it killed bacteria. The study was carried out at the University of Edinburgh in the United Kingdom and it involved the study of chemical compounds called perchlorates that are found on Mars' surface.
Per CNN, Mars is not an ideal planet to live in because of the extreme cold, coupled with blistering radiation, and its thin carbon dioxide atmosphere. A highly oxidized form of chlorine, perchlorates can serve as an energy source for bacteria-a simple food that helps them live off the land.
Bacillus subtilis, a common contaminant found on spacecraft, was destroyed within minutes by conditions similar to those on Mars. When they exposed it to UV waves like those on Mars, the cells became completely sterile within 30 seconds. Upon adding in other components found in Martian soil, iron oxide and hydrogen peroxide, the results were even worse: Bacteria were killed 11 times faster than with just perchlorates. If life could thrive in perchlorate-rich brines, then aliens might be thriving in the damp patches on Mars. "This, combined with the solar and galactic particle radiation environment at the Martian surface, makes it all the more important to sample underneath the surface in the search for biomarkers", he said. As we discover more and more about the composition and planetary dynamics of Mars, there has been cause for both elation and disappointment regarding the likelihood that organic life could manage to eke out a living on the planet.
The results "could have implications for potential contamination from robotic and human exploration of Mars", the statement said, in that those bacteria brought over to Mars by unmanned rovers or, in the future, humans would die quickly and would not pose a huge contamination risk.
The research report concluded that the chemicals found on the surface of Mars effectively rendered "the present-day surface more uninhabitable than previously thought".