https://phys.org/news/2018-06-nasa-ancient-material-mysterious-methane.html

Organic molecules contain carbon and hydrogen, and also may include oxygen, nitrogen and other elements. While commonly associated with life, organic molecules also can be created by non-biological processes and are not necessarily indicators of life. 

"With these new findings, Mars is telling us to stay the course and keep searching for evidence of life," said Thomas Zurbuchen, associate administrator for the Science Mission Directorate at NASA Headquarters, in Washington. "I'm confident that our ongoing and planned missions will unlock even more breathtaking discoveries on the Red Planet."