https://www.cnet.com/news/nasa-did-not-find-life-on-mars-then-accidentally-destroy-organic-molecules/

If you've just been perusing the science headlines this week, you might be under the impression NASA found evidence of life on Mars but accidentally destroyed it. 

To understand the real story, we have to briefly go back to 1976 when NASA's twin Viking landers arrived on the Red Planet and scooped up some Martian dirt. The soil was then heated in the landers' special ovens to allow for an on-board Gas Chromatograph Mass Spectrometer (GCMS) to detect any organic molecules within. To the surprise of many at the time, the results showed the samples appeared to be devoid of any such organics, which are often referred to as the building blocks of life.