A new report suggests that NASA's Viking mission in the 1970s may have discovered evidence of organic matter on Mars, but inadvertently destroyed it by heating samples too much.
The findings, published by New Scientist, indicate that the Viking lander heated Martian soil samples to 500 degrees Celsius, a temperature high enough to burn perchlorate—a toxic compound later found by the Phoenix lander in 2008. This reaction would have also destroyed any complex organic molecules present.
In 2013, NASA's Curiosity rover detected organic molecules and chlorobenzene, which forms when carbon reacts with perchlorate. This suggests that Viking may have encountered similar compounds but burned them during analysis.
The discovery of perchlorate by Phoenix led researchers to re-evaluate Viking's data, raising the possibility that evidence of past life was accidentally incinerated.
