Posted: Sun, Jun 10, 2018, 11:10 AM ET (1510 GMT)

Scientists have discovered organic molecules and varying methane emissions on Mars, findings that that can be explained by both biological and non-biological processes. In one study published Thursday, scientists studying data from the Curiosity Mars rover detected organic molecules in Martian rocks dating back 3.5 billion years. In a second study, Curiosity detected methane in the Martian atmosphere that varied with the planet's seasons. While both results could be explained if Mars had, or has, life, those findings can also be explained by other processes.