A scientist claims that humans found life on Mars 50 years ago, and then killed it accidentally

An astrobiology professor has claimed that life on Mars was discovered 50 years ago but quickly eradicated. Dirk Schulze-Makuch, a faculty member at the Technical University Berlin, has made the sensational claim, saying we may have got lucky with discovering extraterrestrial life, only to destroy it unintentionally. 

Prior to the Curiosity rover, NASA had launched the Viking programme in the mid-1970s – sending two landers to the Martian surface. The mission, ahead of its time, managed to offer the first glimpses of the Martian surface to humankind. Not only that, but the mission also performed biological analysis of its soil, with the primary aim of unearthing indications of life.